Margin: Minified file to use correct path.
MarginBase code refactoring.
LESS: Incorrect method nesting.
Helpers: Handled edge case.
When target file is outside project directory,
ProjectItems.AddFromFile( .. ) throws
COMException: "Webs do not support linked files.

For instance, if custom folder in compiler is
set with absolute or relative path, which yeilds
a location outside the project scope.