* replaced rex with tre in qse_sed_t
* added submatch reference for the 's' command into qse_sed_t
* changed some options and functions for tre integration in qse_sed_t
- refdown_globals() should have been called after qse_awk_rtx_clrrec()
as it still access NF.
fixed typo in awk error messages
fixed a memory allocation bug in matching a group (match_group)
uncommented binary number parsing code in the awk parser.
- changed qse_sed_t to support arbitrary numbers of commands
- added qse_set_getmaxdepth() and qse_sed_setmaxdepth()
- added relevant wrapper functions to QSE::Sed