added command apropos(string)
added command show-bindings(cmd_name)
moved describe-bindings to extras.c
added qe_get_prototype(CmdDef *d, char *buf, int size);
added an extra argument to qe_get_variable() to produce value as source
fixed typo on window variable window-height
fixed type mismatch on mode variable mode-name
added var_domain string array
added strquote conversion function with simplistic implementation
added history tags for all commands
cleaned up Makefile
renamed ModeDef::mode_line function pointer to get_mode_line
fixed some sparse warnings
use c99 syntax in video.c and image.c
added EditBuffer::offset for buffer parsing
added state variables QEmacsState::it, QEmacsState::ignore_spaces,
QEmacsState::mmap_threshold
support variables in config file, strings can be delimited with ' and "
