Blender Git Loki

2.5

- after closing button (having used it), it sends empty mousemove for
invoking new modal handler on same button. Don't know better solution
for now, at least this way WM handles everything. :)

- experiment: moved button handlers to area level, that way it respects
handlers on higher hierarchical level, like moving area edges.
Als interesting is that you can have a button active (texteditor) and
use a similar button in other area.
This can also be done on region level even.

On todo: proper notifier events for redraw! Don't want all areas to draw
on simple refreshes