* gdbtk.c: New tcl commands: gdb_fetch_registers,
gdb_changed_register_list, and gdb_regnames.
* gdbtk.tcl: Use monochrome color model for now.
* (delete_breakpoint_tag create_file_win): Add breakdot support.
* (create_file_win create_asm_win update_listing build_framework
create_source_window create_command_window): Re-org window
creation to give all windows consistent look and feel.
* (update_listing update_asm): Change pc pointer to '->'.
* (registers_command reg_config_menu create_registers_window
populate_reg_window update_registers): Revamp register window.
Allow selection of registers to be displayed. Highlight changed
registers.