libuv 0.10.31

Closes #600.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
bison27: add 2.7.1 bottle.
llvm31 and llvm32 have been moved to homebrew-boneyard

...and are no longer supported. This repository will maintain formulae
for the three most recent versions of llvm.
llvm3[345]: fix path in caveats
llvm3[345]: bottle against system python
llvm3[345]: use absolute dylib IDs
llvm33: update 3.3_1 bottle.
llvm34: update 3.4.2 bottle.
llvm35: update 3.5.0 bottle.
gcc48: remove outdated bottle checksums

These bottles were added for 4.8.2 and are no longer valid.
gcc48 4.8.4
gcc48: sandbox within series release number only
gcc48: add 4.8.4 bottle.