Merge pull request #1 from marianela4711/master

Added set/unset proxy cli option and function..
Merge pull request #2 from marianela4711/master

Moving NIXPKGS_REPO out of the shell script
Die in bad environment
Adding crude expressions sync
cleanup and guards
Use unstable when setting/unsetting proxy
Build vm helper
REPL fixup
List latest commit built by hydra for channel
Case parens..
Cleaning system requires root..
There is really only one channel I care about
Grub rewinder and fixer..
32 and 64 bit linux builders
Adding shell
Adding optimize
Set proxy shouldn't require work
Really change proxy without rebuilds
nix-build doesn't honour NIX_PATH?
Sisyphus