Cast WhiteSpace Sniff

This is my first attempt at creating a sniff, on testing on my own
plugin code it seemed to work well, gave the correct errors and no
false positives. It may not be named correctly or in the right place to
meet CodeSniff standards.
Unit Tests for CastStructureSpacing
Correct the Unit Test filenames

Original Unit Test file names were incorrect
Correct Unit Test Class Name
Change to Warnings

Change from Errors to Warnings and update line return encoding on the
Sniff file
Merge pull request #217 from mattyrob/master

Cast WhiteSpace Sniff