Actually allow editing (and some other fixes)

Home/End move the the expected place.
CTRL-Q now quits, not Q
CTRL-R "runs" a message (ie: doesn't abort) useful for @EXEC:noyesbar@
CTRL-Z undoes all changes (reloads text.dat value)
CTRL-V allows entering a hex value
^ allows entering a CTRL-code
\ allows an escape character