Remove target_read_live_memory

Remove target_read_live_memory

As we move code on reading unavailable memory to target side, GDB core
side doesn't need the "switching momentarily out of tfind mode" dance.
The target remote knows how to read live memory (through remote_ops).

Remove set_traceframe_number and
make_cleanup_restore_traceframe_number, since they are no longer used.

gdb:

2014-03-22  Yao Qi  <yao@codesourcery.com>

	* remote.c (target_read_live_memory): Remove.
	(memory_xfer_live_readonly_partial): Rename it to
	remote_xfer_live_readonly_partial.  Remove argument 'object'.
	All callers updated.  Call remote_read_bytes_1
	instead of target_read_live_memory.
	* tracepoint.c (set_traceframe_number): Remove.
	(make_cleanup_restore_traceframe_number): Likewise .
	* tracepoint.h (set_traceframe_number): Remove declaration.
	(make_cleanup_restore_traceframe_number): Likewise.