Rename the type AsyncEventCallback to AsyncEventHandler. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7948 91a5dbb7-01b9-0310-9b5f-b28072856b6e
Restore the side effect of CSRTRK+on also implying HOME. (dm)


git-svn-id: svn://mielke.cc/main/brltty@7949 91a5dbb7-01b9-0310-9b5f-b28072856b6e