opening result text file.

column 0 and now ignores blank lines.

from unlocking the mutex (Win32 critical section) when it hasn't been locked
(outside of input_thread).

LockCount before unlocking to prevent lock-up (indefinite wait) situation.

implementation uses CriticalSections, it would lock the input_thread by leaving
(releasing) the critical section when it didn't own it.

(needed for alarm signals in rz).

Unified the StartWithMsg# logic in the 'L' and 'F' commands and made it more
"logical".
Fixed bug when aborting the 'L' command while in const-scan or find mode;
would abort the entire read prompt.

Bugfix: binary externals (transfer protocols) now use raw terminal setup.

(in addition to the output buffer), and eats the entire packet.
outcom() now returns TXBOF if the RingBufWrite() call fails.

(*much* faster!).