Rename some trace functions

Rename some trace functions

This patch renames a few trace-related functions, so that they adhere to
the de facto standard of naming command entry point functions
<command>_command.  I like the ease of looking up a command entry point
if they all follow that rule.

An enum label "tstop_command" conflicts with a new function name, so I
renamed this one trace_stop_command.

In v2:

- Rename functions of the trace_find family, as well as
  trace_dump_command.

gdb/ChangeLog:

	* tracefile-tfile.c (tfile_write_status): Adjust to renames.
	* tracefile.c (trace_save_command): Rename to...
	(tsave_command): ...this.
	(_initialize_tracefile): Adjust to renames.
	* tracepoint.c (trace_actions_command): Rename to...
	(actions_command): ...this.
	(trace_start_command): Rename to...
	(tstart_command): ...this, and adjust to renames..
	(trace_stop_command): Rename to...
	(tstop_command): ...this.
	(trace_status_command): Rename to...
	(tstatus_command): ...this, and adjust to renames.
	(trace_find_command): Rename to...
	(tfind_command): ...this.
	(trace_find_pc_command): Rename to...
	(tfind_pc_command): ...this.
	(trace_find_tracepoint_command): Rename to...
	(tfind_tracepoint_command): ...this.
	(trace_find_line_command): Rename to...
	(tfind_line_command): ...this.
	(trace_find_range_command): Rename to...
	(tfind_range_command): ...this.
	(trace_find_outside_command): Rename to...
	(tfind_outside_command): ...this.
	(trace_dump_command): Rename to...
	(tdump_command): ...this.
	(tfind_1): Adjust to renames.
	(trace_find_end_command): Rename to...
	(tfind_end_command): ...this, and adjust to renames..
	(trace_status_mi): Adjust to renames.
	(parse_trace_status): Adjust to renames.
	(_initialize_tracepoint): Adjust to renames.
	* tracepoint.h (enum trace_stop_reason) <tstop_command>: Rename
	to...
	<trace_stop_command>: ...this.