Bugfix: Continue combat after having seen the combat log

* Previously, combat was stopped when entering the combat log. This commit makes the combat continue after having been stopped.
Bugfix: Redraw whole screen if double-buffer is not pre-filled

* Fixes issue where the screen was only partially drawn after having entered heroinfoactivity before starting combat.
* lockCanvas() changes the supplied Rect object occasionally, to indicate that the double buffer has not been filled. In those cases, you need to redraw the whole rect.