Cleaned up build process:

- Package restore was enabled.
- Package versions were removed from nuspecs (it fills from scripts during build process)
- Added one NuGet.exe (one NuGet shared between VS and FAKE)
- Packages and tools\FAKE removed from repo.
- Fixed FAKE install commands
Merge branch 'master' of https://github.com/lefthandedgoat/canopy
Merge pull request #112 from sergey-tihon/master

Build process was cleaned up.