update progress bar documentation
update progress bar documentation

clarify lack of support for striped and animated striped bars in
IE10+/Edge

onenameio/rhythm-bootstrap,tjkohli/bootstrap,stanwmusic/bootstrap,9-chirno/chirno,IdanCo/bootstrap,coliff/bootstrap,JumpLinkNetwork/bootstrap-backward,jipexu/bootstrap,slavanga/bootstrap,yuyokk/bootstrap,johnajacob/bootstrap,SweetProcess/bootstrap,TheFridayInstitute/bootstrap,twbs/bootstrap,slavanga/bootstrap,nice-fungal/bootstrap,creativewebjp/bootstrap,tomlutzenberger/bootstrap,seanwu99/bootstrap,sealocal/bootstrap,bootstrapbrasil/bootstrap,igoynawamreh/bootstrap,edanbarak/bootstrap,SweetProcess/bootstrap,fschumann1211/bootstrap,Lyricalz/bootstrap,blockstack/blockstack-bootstrap,janseliger/bootstrap,Delagen/bootstrap,supergibbs/bootstrap,Scoutski/bootstrap,JumpLinkNetwork/bootstrap-backward,davethegr8/bootstrap,zalog/bootstrap,xt0rted/bootstrap,inway/bootstrap,jipexu/bootstrap,lemuelbarango/bootstrap,coliff/bootstrap,xt0rted/bootstrap,david-schopf/bootstrap,TheFridayInstitute/bootstrap,NCARB/bootstrap,vitaligent/4,tomlutzenberger/bootstrap,Hightrack/bootstrap,yuyokk/bootstrap,creativewebjp/bootstrap,nice-fungal/bootstrap,Lyricalz/bootstrap,n054/bootstrap,afuno/bootstrap,afuno/bootstrap,supergibbs/bootstrap,igoynawamreh/bootstrap,copperdesign/bootstrap,johnajacob/bootstrap,yuyokk/bootstrap,edanbarak/bootstrap,IdanCo/bootstrap,inway/bootstrap,lipis/bootstrap,kvlsrg/bootstrap,andresgalante/bootstrap,fschumann1211/bootstrap,joblocal/bootstrap,hebbet/bootstrap,abvalentine/bootstrap,nice-fungal/bootstrap,wesamco/bootstrap-rtl,tibo66/bootstrap,frostbitten/bootstrap,gijsbotje/bootstrap,wesamco/bootstrap-rtl,SweetProcess/bootstrap,tagliala/bootstrap,Hemphill/bootstrap-docs,creativewebjp/bootstrap,Scoutski/bootstrap,copperdesign/bootstrap,hebbet/bootstrap,stanwmusic/bootstrap,inway/bootstrap,hebbet/bootstrap,twbs/bootstrap,hebbet/bootstrap,supergibbs/bootstrap,IdanCo/bootstrap,NCARB/bootstrap,edanbarak/bootstrap,Hemphill/bootstrap-docs,vitaligent/4,realcrowd/bootstrap,blockstack/blockstack-bootstrap,Hemphill/bootstrap-docs,bardiharborow/bootstrap,joblocal/bootstrap,tibo66/bootstrap,andresgalante/bootstrap,9-chirno/chirno,bootstrapbrasil/bootstrap,Hightrack/bootstrap,Lyricalz/bootstrap,kvlsrg/bootstrap,lemuelbarango/bootstrap,Hemphill/bootstrap-docs,seanwu99/bootstrap,johnajacob/bootstrap,n054/bootstrap,slavanga/bootstrap,davethegr8/bootstrap,JumpLinkNetwork/bootstrap-backward,stanwmusic/bootstrap,bardiharborow/bootstrap,blockstack/blockstack-bootstrap,tjkohli/bootstrap,NCARB/bootstrap,david-schopf/bootstrap,fschumann1211/bootstrap,realcrowd/bootstrap,xt0rted/bootstrap,johnajacob/bootstrap,realcrowd/bootstrap,lipis/bootstrap,wesamco/bootstrap-rtl,tagliala/bootstrap,onenameio/rhythm-bootstrap,fschumann1211/bootstrap,Hightrack/bootstrap,afuno/bootstrap,davethegr8/bootstrap,gijsbotje/bootstrap,zalog/bootstrap,tagliala/bootstrap,frostbitten/bootstrap,andresgalante/bootstrap,joblocal/bootstrap,afuno/bootstrap,lemuelbarango/bootstrap,yuyokk/bootstrap,jipexu/bootstrap,n054/bootstrap,onenameio/rhythm-bootstrap,abvalentine/bootstrap,GerHobbelt/bootstrap,GerHobbelt/bootstrap,gijsbotje/bootstrap,Delagen/bootstrap,stanwmusic/bootstrap,gijsbotje/bootstrap,Lyricalz/bootstrap,igoynawamreh/bootstrap,Scoutski/bootstrap,Delagen/bootstrap,david-schopf/bootstrap,janseliger/bootstrap,vsn4ik/bootstrap,realcrowd/bootstrap,supergibbs/bootstrap,GerHobbelt/bootstrap,bardiharborow/bootstrap,slavanga/bootstrap,seanwu99/bootstrap,davethegr8/bootstrap,vitaligent/4,sealocal/bootstrap,bardiharborow/bootstrap,frostbitten/bootstrap,TheFridayInstitute/bootstrap,JumpLinkNetwork/bootstrap-backward,vsn4ik/bootstrap,Scoutski/bootstrap,TheFridayInstitute/bootstrap,Delagen/bootstrap,lipis/bootstrap,lipis/bootstrap,IdanCo/bootstrap,creativewebjp/bootstrap,n054/bootstrap,igoynawamreh/bootstrap,edanbarak/bootstrap,janseliger/bootstrap,jipexu/bootstrap,sealocal/bootstrap,copperdesign/bootstrap,abvalentine/bootstrap,peterblazejewicz/bootstrap,tibo66/bootstrap,SweetProcess/bootstrap,vsn4ik/bootstrap,kvlsrg/bootstrap,vsn4ik/bootstrap,lemuelbarango/bootstrap,wesamco/bootstrap-rtl,bootstrapbrasil/bootstrap,tomlutzenberger/bootstrap,9-chirno/chirno,9-chirno/chirno,joblocal/bootstrap,frostbitten/bootstrap,seanwu99/bootstrap,peterblazejewicz/bootstrap,zalog/bootstrap,andresgalante/bootstrap,sealocal/bootstrap,tibo66/bootstrap,janseliger/bootstrap,abvalentine/bootstrap,peterblazejewicz/bootstrap,xt0rted/bootstrap,m5o/bootstrap,m5o/bootstrap,copperdesign/bootstrap,NCARB/bootstrap