Changes to Flag, Globals, and Mapwalk

Updated Flag.simba, still need to fix FlagEx and MouseFlagEx.
Changed screen constants (Mxxx constants) as they were not to my liking,
and are now exact.
Removed ClickNorth() as the feature does not exist in '07 Runescape.
Merge pull request #24 from euphemism/master

Changed Flag, Globals, and Mapwalk