return a non-zero error code if the PipedCommand was not successful
return non-success error code in the other case as well
Merge pull request #20 from colekowalski/exitcode

return a non-zero error code if the PipedCommand was not successful
Updated gitignore
Improved git clone and checkout logic
Brian didn't know about TrimSpace
Fixed hg clone bug
Impoved TrimmedCmd and suppressed some git out about detached HEAD
Merge pull request #22 from kinghrothgar/master

Improved the git and hg logic in deps package and some changes to exec
update the README to be a bit more friendly