Merge pull request #301 from uhaciogullari/master

StringExtensions.ToLowercaseUnderscore does not use InvariantCulture
Merge pull request #302 from uhaciogullari/master

Ignore NCrunch files
Merge pull request #303 from uhaciogullari/master

Char.ToLower with CultureInfo parameter is not supported in WinRT
fixed compilation issues for Mono