Custom line processors are considered "code" by FilePreProcessor. #630

FilePreProcessor.IsNonDirectiveLine only considers #r and #load directives. Custom directives will be considered code and in the following situation, #load would be ignored.

#gist 10731562
#load "someScript.csx"

Here is my proposed solution with some suggestions from @khellang https://gist.github.com/ryanrousseau/10731562