Added cscript.ado.

It is a copy of the StataCorp command:
*! version 3.6.0  04mar2013
Trimmed trailing white space.
Renamed cscript.ado as cscript_git.ado.
-cscript_git- does not drop select globals.
Added -matawarn-.
Merge branch 'cscript'

Added general cscript ado-files.
Moved -stgit- files to subdirectory.
Removed -cscript_git-.