Remove dependency on Sake

[natemcmaster]

This is a non-trivial change. Lots of our build scripts are written in Sake. This code has to be ported to MSBuild or powershell before we can remove Sake completely.

[davidfowl]

RIP sake

[natemcmaster]

As a part of this @pranavkm and I want to change out our build scripts handle trailing arguments ($@). New syntax would add trailing args to the main MSBuild invocation. e.g. build.cmd /t:TargetName. Would let us to things like build.cmd /p:CoreFxVersion=4.4.0-nightly /v:normal /logger:CustomLogger etc.