Merge pull request #139 from patriksvensson/develop

Renamed script alias classes to use the correct terminology.
Deduplicated NuGet GetDefaultToolPath
Added a core NuGetToolResolver for the any code that utilizes the nuget.exe like for example the NuGet Tool<T>:s
Extended it so it
  1. Caches path if found
  2. Not only checks via globber pattern but now does several steps
    1. NUGET_EXE environment variable
    2. Globber "./tools/**/NuGet.exe"
    3. If exists in environment path
Merge pull request #141 from devlead/nugetfromenv

Deduplicated NuGet GetDefaultToolPath
Merge branch 'develop' of github.com:patriksvensson/cake into develop