Fix some bugs in Aenea

1. dragonfly uses lessthan and greaterthan but Aenea uses less and greater; this makes it impossible to use Aenea Key actions involving '<' or '>'
2. Fixed broken Mouse actions.  Previously, args and kw args were not passed up to base classes resulting in a missing self._spec
3. Fixed the linux server to handle negative arguments for mouse actions correctly; previously, it did not pass the proper commands to xdotool which caused errors
4. Fixed _make_mouse_parser to allow negative numbers
5. Added missing self._str values in various Aenea context classes.  This caused errors when attempting to combine contexts in various ways before