Implement Borrow<CStr> for CString and ToOwned for CStr
Implement Borrow<CStr> for CString and ToOwned for CStr

This allows CString and CStr to be used with the Cow type,
which is extremely useful when interfacing with C libraries
that make extensive use of C-style strings.

jroesch/rust,GBGamer/rust,GBGamer/rust,pshc/rust,l0kod/rust,vhbit/rust,pshc/rust,nwin/rust,nwin/rust,GBGamer/rust,GBGamer/rust,nwin/rust,dwillmer/rust,aidancully/rust,vhbit/rust,vhbit/rust,jashank/rust,dwillmer/rust,graydon/rust,jroesch/rust,jashank/rust,aidancully/rust,GBGamer/rust,l0kod/rust,dwillmer/rust,l0kod/rust,dwillmer/rust,dwillmer/rust,jashank/rust,vhbit/rust,nwin/rust,vhbit/rust,vhbit/rust,pshc/rust,nwin/rust,zubron/rust,zubron/rust,zubron/rust,zubron/rust,l0kod/rust,pshc/rust,jashank/rust,graydon/rust,pshc/rust,GBGamer/rust,jashank/rust,aidancully/rust,zubron/rust,vhbit/rust,jroesch/rust,graydon/rust,vhbit/rust,graydon/rust,GBGamer/rust,graydon/rust,zubron/rust,jroesch/rust,aidancully/rust,pshc/rust,jroesch/rust,aidancully/rust,nwin/rust,l0kod/rust,nwin/rust,GBGamer/rust,l0kod/rust,l0kod/rust,l0kod/rust,pshc/rust,jashank/rust,pshc/rust,jroesch/rust,jroesch/rust,aidancully/rust,graydon/rust,zubron/rust,jashank/rust,jashank/rust,dwillmer/rust,dwillmer/rust,nwin/rust,jroesch/rust,dwillmer/rust,zubron/rust