configure: Accept LLVM 3.4.X during configuration
configure: Accept LLVM 3.4.X during configuration

The previous regex was a bit to strict, rejecting versions such as 3.4.1 which
is apparently the version which travis is currently installing, causing all
travis builds to fail.

erickt/rust,GBGamer/rust,miniupnp/rust,andars/rust,sae-bom/rust,aturon/rust,pczarn/rust,reem/rust,omasanori/rust,pythonesque/rust,stepancheg/rust-ide-rust,ktossell/rust,stepancheg/rust-ide-rust,0x73/rust,erickt/rust,zachwick/rust,robertg/rust,arthurprs/rand,richo/rust,ebfull/rust,aidancully/rust,jroesch/rust,zaeleus/rust,AerialX/rust-rt-minimal,mihneadb/rust,michaelballantyne/rust-gpu,aturon/rust,pshc/rust,kwantam/rust,zubron/rust,avdi/rust,ejjeong/rust,aepsil0n/rust,bombless/rust-docs-chinese,quornian/rust,rprichard/rust,rohitjoshi/rust,richo/rust,rohitjoshi/rust,servo/rust,pythonesque/rust,ruud-v-a/rust,gifnksm/rust,graydon/rust,andars/rust,ejjeong/rust,jashank/rust,bhickey/rand,quornian/rust,graydon/rust,dinfuehr/rust,AerialX/rust,michaelballantyne/rust-gpu,bombless/rust,zubron/rust,l0kod/rust,carols10cents/rust,TheNeikos/rust,nham/rust,emk/rust,zaeleus/rust,dwillmer/rust,P1start/rust,XMPPwocky/rust,jbclements/rust,rohitjoshi/rust,ebfull/rust,richo/rust,dinfuehr/rust,l0kod/rust,seanrivera/rust,emk/rust,mvdnes/rust,TheNeikos/rust,jashank/rust,aneeshusa/rust,aepsil0n/rust,retep998/rand,nwin/rust,aneeshusa/rust,defuz/rust,jbclements/rust,jroesch/rust,AerialX/rust-rt-minimal,nwin/rust,philyoon/rust,erickt/rust,zubron/rust,pczarn/rust,avdi/rust,GBGamer/rust,pythonesque/rust,mvdnes/rust,sae-bom/rust,pythonesque/rust,gifnksm/rust,nham/rust,jroesch/rust,aidancully/rust,quornian/rust,ruud-v-a/rust,Ryman/rust,zachwick/rust,pshc/rust,mihneadb/rust,XMPPwocky/rust,kimroen/rust,pythonesque/rust,zachwick/rust,AerialX/rust,sae-bom/rust,miniupnp/rust,pczarn/rust,aidancully/rust,hauleth/rust,zachwick/rust,ebfull/rust,aidancully/rust,servo/rust,graydon/rust,mvdnes/rust,servo/rust,dinfuehr/rust,jbclements/rust,mdinger/rust,rprichard/rust,jashank/rust,bombless/rust,vhbit/rust,philyoon/rust,ktossell/rust,vhbit/rust,barosl/rust,robertg/rust,XMPPwocky/rust,victorvde/rust,TheNeikos/rust,mvdnes/rust,sae-bom/rust,ktossell/rust,richo/rust,kwantam/rust,kwantam/rust,P1start/rust,krzysz00/rust,avdi/rust,nwin/rust,dwillmer/rust,mdinger/rust,jbclements/rust,jroesch/rust,michaelballantyne/rust-gpu,hauleth/rust,stepancheg/rust-ide-rust,0x73/rust,pshc/rust,aturon/rust,jashank/rust,mdinger/rust,robertg/rust,AerialX/rust,aneeshusa/rust,vhbit/rust,pythonesque/rust,richo/rust,XMPPwocky/rust,mihneadb/rust,kimroen/rust,michaelballantyne/rust-gpu,avdi/rust,zubron/rust,zaeleus/rust,sae-bom/rust,quornian/rust,mihneadb/rust,cllns/rust,cllns/rust,bombless/rust,pelmers/rust,pshc/rust,andars/rust,barosl/rust,aturon/rust,0x73/rust,dwillmer/rust,zubron/rust,rohitjoshi/rust,jbclements/rust,gifnksm/rust,servo/rust,dwillmer/rust,graydon/rust,philyoon/rust,untitaker/rust,pczarn/rust,jroesch/rust,ejjeong/rust,aidancully/rust,jashank/rust,barosl/rust,gifnksm/rust,robertg/rust,victorvde/rust,ejjeong/rust,pshc/rust,pshc/rust,AerialX/rust,untitaker/rust,krzysz00/rust,jbclements/rust,dinfuehr/rust,nham/rust,nwin/rust,mahkoh/rust,aepsil0n/rust,dwillmer/rust,XMPPwocky/rust,stepancheg/rust-ide-rust,aepsil0n/rust,ruud-v-a/rust,rprichard/rust,reem/rust,Ryman/rust,andars/rust,hauleth/rust,hauleth/rust,dinfuehr/rust,GBGamer/rust,rohitjoshi/rust,emk/rust,mahkoh/rust,Ryman/rust,0x73/rust,dwillmer/rust,ktossell/rust,jashank/rust,victorvde/rust,KokaKiwi/rust,ejjeong/rust,nwin/rust,zaeleus/rust,barosl/rust,mdinger/rust,jbclements/rust,nham/rust,zachwick/rust,miniupnp/rust,Ryman/rust,nham/rust,carols10cents/rust,mdinger/rust,krzysz00/rust,quornian/rust,l0kod/rust,erickt/rust,zachwick/rust,ebfull/rand,ktossell/rust,dinfuehr/rust,GBGamer/rust,aneeshusa/rust,ruud-v-a/rust,mihneadb/rust,pelmers/rust,quornian/rust,seanrivera/rust,reem/rust,avdi/rust,erickt/rust,omasanori/rust,sae-bom/rust,ebfull/rust,zubron/rust,defuz/rust,Ryman/rust,TheNeikos/rust,P1start/rust,zaeleus/rust,bluss/rand,jbclements/rust,dwillmer/rust,kimroen/rust,ebfull/rust,XMPPwocky/rust,omasanori/rust,achanda/rand,aepsil0n/rust,mahkoh/rust,GBGamer/rust,P1start/rust,seanrivera/rust,mdinger/rust,pshc/rust,kimroen/rust,stepancheg/rust-ide-rust,vhbit/rust,ruud-v-a/rust,rprichard/rust,untitaker/rust,bombless/rust,jbclements/rust,pshc/rust,aneeshusa/rust,0x73/rust,GBGamer/rust,miniupnp/rust,cllns/rust,pczarn/rust,reem/rust,servo/rust,TheNeikos/rust,carols10cents/rust,mvdnes/rust,robertg/rust,shepmaster/rand,kimroen/rust,erickt/rust,jashank/rust,l0kod/rust,kimroen/rust,mahkoh/rust,emk/rust,kwantam/rust,barosl/rust,jashank/rust,nwin/rust,untitaker/rust,jroesch/rust,gifnksm/rust,defuz/rust,servo/rust,AerialX/rust,miniupnp/rust,vhbit/rust,avdi/rust,nham/rust,bombless/rust,AerialX/rust,waynenilsen/rand,michaelballantyne/rust-gpu,seanrivera/rust,jroesch/rust,rprichard/rust,graydon/rust,bombless/rust,hauleth/rust,barosl/rust,robertg/rust,aidancully/rust,AerialX/rust-rt-minimal,l0kod/rust,krzysz00/rust,zubron/rust,philyoon/rust,ktossell/rust,0x73/rust,krzysz00/rust,miniupnp/rust,defuz/rust,mihneadb/rust,vhbit/rust,graydon/rust,GrahamDennis/rand,P1start/rust,pczarn/rust,GBGamer/rust,mahkoh/rust,aturon/rust,rprichard/rust,KokaKiwi/rust,AerialX/rust-rt-minimal,pelmers/rust,huonw/rand,emk/rust,carols10cents/rust,untitaker/rust,KokaKiwi/rust,emk/rust,nham/rust,aneeshusa/rust,0x73/rust,KokaKiwi/rust,andars/rust,AerialX/rust-rt-minimal,GBGamer/rust,nwin/rust,kwantam/rust,vhbit/rust,pythonesque/rust,ktossell/rust,l0kod/rust,krzysz00/rust,reem/rust,aturon/rust,omasanori/rust,quornian/rust,vhbit/rust,stepancheg/rust-ide-rust,rohitjoshi/rust,P1start/rust,barosl/rust,victorvde/rust,cllns/rust,P1start/rust,ebfull/rust,ruud-v-a/rust,philyoon/rust,l0kod/rust,cllns/rust,nwin/rust,reem/rust,KokaKiwi/rust,omasanori/rust,victorvde/rust,carols10cents/rust,ejjeong/rust,kwantam/rust,andars/rust,omasanori/rust,Ryman/rust,pelmers/rust,philyoon/rust,aturon/rust,victorvde/rust,hauleth/rust,pelmers/rust,defuz/rust,miniupnp/rust,kimroen/rust,stepancheg/rust-ide-rust,miniupnp/rust,zaeleus/rust,jroesch/rust,erickt/rust,defuz/rust,mvdnes/rust,richo/rust,seanrivera/rust,aepsil0n/rust,gifnksm/rust,zubron/rust,TheNeikos/rust,dwillmer/rust,michaelballantyne/rust-gpu,KokaKiwi/rust,mahkoh/rust,Ryman/rust,seanrivera/rust,michaelballantyne/rust-gpu,untitaker/rust,servo/rust,pelmers/rust,cllns/rust,pczarn/rust,AerialX/rust-rt-minimal,l0kod/rust,carols10cents/rust,emk/rust