Made changes to lineterm, especially the PTY code, to get it to compile on
FreeBSD (bug 32923). Now it does compile and run on FreeBSD. There still a few
glitches though; PTY resizing fails in FreeBSD, for example.
Minor tweaks to handle input of control characters. Switched to double clicks, instead of single clicks, to activate XMLterm features (to protect the user).
Implemented full screen operations in XMLTerm, although still buggy.
Commands like 'less', 'vi', and 'emacs -nw' now work in stand-alone xmlterm,
although scrolling is still messed up. Compiles with Feb21 tree.