Finish reviving learn mode. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7801 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Ensure that only one update thread is executing. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7802 91a5dbb7-01b9-0310-9b5f-b28072856b6e
scr.auto.h needs to know the definition of ScreenDriver. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7803 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Move pre- and post-processing of a command out of the navigation command handler. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7804 91a5dbb7-01b9-0310-9b5f-b28072856b6e
BRL_CMD_OFFLINE should only be applied to braille device (not keyboard) commands. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7805 91a5dbb7-01b9-0310-9b5f-b28072856b6e