mrxvt Code

Made ATAB_EXTRA_PERCENT a configure option. Also made radius of tab corners a
configure option.

replace the ugly hack for compiling openbsd with another ugly one

apply patches from freebsd ports

Changed C++ style comments to C style

1. Setting the tab title via \e]0 behaves like \e]2 (i.e. depending on macros
defined in src/feature.h, sets only the tab title or sets the tab and window
title respectively).
2. Modified PrintScreen macro so that it can be used to save your buffer to a
temp file, and open it in a new tab with less / vim. Useful for searching /
cut + paste.
3. Save config file now profile compliant (may be this was already done on my
last commit ...?)
4. Renamed the mrxvt escape sequences from Xterm_xx to MRxvt_xx.

replace c++ style comments with c style comments

fix working directory when we spawn child process - the current code only works for linux

replace obsolete -tnum option with -ip option for session support

replace obsolete -tnum option with -ip option

Fixed crash on Tru64 (thanks to Teun Burgers)