Added GAP lexer.
Added GAP lexer.

R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone,R1dO/scintilla_clone