* gtkutil.c: Include signal.h and syssignal.h.

* gtkutil.c: Include signal.h and syssignal.h.
(xg_get_file_name): Block and unblock __SIGRTMIN if defined.

* alloc.c: If HAVE_GTK_AND_PTHREAD, include pthread.h,
new variables main_thread and alloc_mutex,
define (UN)BLOCK_INPUT_ALLOC to use alloc_mutex to protect
emacs_blocked_* calls and only do (UN)BLOCK_INPUT in the main thread.
If not HAVE_GTK_AND_PTHREAD, (UN)BLOCK_INPUT_ALLOC is the same as
(UN)BLOCK_INPUT.
(emacs_blocked_free, emacs_blocked_malloc)
(emacs_blocked_realloc): Use (UN)BLOCK_INPUT_ALLOC.
(uninterrupt_malloc): Initialize main_thread and alloc_mutex.
(reset_malloc_hooks): New function.

* lisp.h: Declare reset_malloc_hooks.

* emacs.c (Fdump_emacs): Call reset_malloc_hooks.

* keyboard.c: Conditionally include pthread.h
(handle_async_inpu, input_available_signalt): If not in the main
thread, block signal, send signal to main thread and return.