New features and bugs fixed:
- mouse support: new command /mouse, new option weechat.look.mouse, new key context "mouse"
- free movement of cursor: new command /cursor, new key context "cursor"
- new hook_focus (used by cursor and mouse)
- info "cursor_mode"
- bugs fixed with key "^"
- allow plugin name in /buffer name
- fix bugs with bar windows: do not create bar windows for hidden bars
- fix completion bug when two words for completion are equal but with different case
- automatic scroll direction in /bar scroll (x/y is now optional)
