gdb/testsuite/

gdb/testsuite/
	* gdb.python/py-events.exp: Remove pretty printing comment.
	* gdb.python/py-evsignal.exp: New file.
	* gdb.python/py-evthreads.c: Include signal.h.
	(thread3): Remove variable count3.  Remove variable bad and use raise
	instead.
	(thread2): Remove variable count2.  Move thread3 pthread_create here,
	merge pthread_join to a single line.
	(main): Remove variable count1.  Merge pthread_join with pthread_create
	to a single line.
	* gdb.python/py-evthreads.exp: Remove pretty printing comment.  New
	KFAIL python/12966 for gdbserver.  Test return value of
	gdb_compile_pthreads.  Use gdb_run_cmd.  Replace send_gdb and
	gdb_expect by gdb_test and gdb_test_multiple.
	(thread 2, thread 3): New tests.