Correct inaccurate regex for convention and fm variables.

I believe my regex for local and global variables is more accurate and for the time being am reverting it to that version. See [Set Variable](http://www.filemaker.com/help/html/scripts_ref1.36.15.html) and [About naming fields](http://www.filemaker.com/help/html/scripts_ref1.36.15.html) in the FileMaker help files regarding disallowed characters in variable names. Also `\s` disallows all whitespace instead of `[^ ]`, which only disallows spaces.