Calls to wm->show_keyboard depend on TOUCH_UI, not __ANDROID__.

In case we ever need to do this for non-Android touchscreen devices.

In the event that we undefine TOUCH_UI while on Android, the keyboard
once again pops up on init.
Properly generate dat/tiles/*.png from rltiles on install-data.
Add a button to show the keyboard on touch UIs.

Complete with Grunt tile, which probably should be replaced.