Move savestring to common/common-utils.c, make gdbserver use it.

Move savestring to common/common-utils.c, make gdbserver use it.

This makes gdbserver share gdb's savestring, instead of baking its own.

Tested on x86_64 Fedora 17.

gdb/
2013-02-14  Pedro Alves  <palves@redhat.com>

	* utils.c (savestring): Don't #undef it.  Move function to
	common/common-utils.c.
	* common/common-utils.c: Include gdb_string.h.
	(savestring): Move here from utils.c.
	* common/common-utils.h (savestring): Declare.

gdb/gdbserver/
2013-02-14  Pedro Alves  <palves@redhat.com>

	* tracepoint.c (save_string): Delete.
	(add_tracepoint_action): Use savestring instead of save_string.