std::rt: Try stealing from all schedulers

This guarantees that if there is work to do it will be found
Update version numbers to 0.8
Pass --disable-terminfo to LLVM's configure script. Closes #9334

The right way to link to terminfo varies by linux distribution, so
this is making our snapshots less compatible.
auto merge of #9353 : brson/rust/sched, r=alexcrichton,cmr

This guarantees that if there is work to do it will be found
auto merge of #9399 : brson/rust/tinfo, r=thestinger

The right way to link to terminfo varies by linux distribution, so
this is making our snapshots less compatible.
Remove 'copy' from syntax files, as it's no longer a keyword
auto merge of #9401 : bytbox/rust/master, r=thestinger

Along with a tiny bit of cleanup in rust.vim.
auto merge of #9395 : brson/rust/0.8, r=alexcrichton