Extend command dispatch system:
- add CMD_ARG_OPAQUE argument type
- add ISS and ISSi command signatures for ISearchState
- add CMDx() macro for disabled and future commands
- restrict command set in parsers
- add opaque argument for exec_command()
- add sort-region command, same as sort-lines
Extend binding system:
- move do_unset_key() from extras.c to qe.c
- accept bindings lists in unset-key commands
- add exact argument for qe_find_binding()
- reorder xxx_bindings arrays
Improve emulation functions:
- improve set-emulation command:
- add xxx_bindings arrays for emulations
- add register_emulation_bindings()
Search system:
- use exec_command to dispatch isearch functions
this allows easy redefinition of bindings, especially
useful for emacs flavor emulations
- add isearch_commands[] with bindings and command descriptions
- bumped version to 5.3.4g
4475afab01