-Wpointer-sign: python/.

-Wpointer-sign: python/.

This fixes -Wpointer-sign warnings in the python/ code in the manner
that seems most appropriate to me.

gdb/
2013-04-19  Pedro Alves  <palves@redhat.com>

	* python/py-inferior.c (infpy_write_memory): Add cast to gdb_byte
	* python/py-prettyprint.c (print_string_repr): Change type of
	'output' local to char *.  Add cast to gdb_byte * in
	LA_PRINT_STRING call.
	(print_children): Change type of 'output' local to char *.
	* python/py-value.c (valpy_string): Add cast to const char * in
	PyUnicode_Decode call.