Added Build base script and NuGet.exe

Base setup for FAKE: added NuGet.exe in tools folder, and build.bat /
build.fsx.
Clean & Build added to build script.
AssemblyInfo, nuspec and NuGet build

Added AssemblyInfo.fs and nuspec file.
Completed build to create NuGet package.
Merge pull request #25 from mathias-brandewinder/master

Automated NuGet package build using FAKE
Update README.md
Update README.md
Update README.md
Update README.md
Support package restore
More graceful processing of absent R install
Merge pull request #30 from geandbe/master

More graceful processing of absent R install
Refactored issue #29; addressed issue #1 with R_HOME
Merge pull request #31 from geandbe/master

Refactored issue #29; addressed issue #1 with R_HOME
Quote function name

Calling a function without quotation fails when the function is an operator.
Merge pull request #32 from kos59125/callOp

Quote function name
RProvider was switched to R.NET 1.5.4 from NuGet
Merge pull request #35 from sergey-tihon/master

RProvider was switched to R.NET 1.5.4 from NuGet
Added script that copy R.NET binaries to RProvider folder after NuGet package install
Fixed bugs in init.ps1
Merge pull request #36 from sergey-tihon/master

Added script that copy R.NET binaries to RProvider folder after NuGet package install