MFC r287341,r287342,r287348:

r287341 (by rodrigc):

Use ANSI C prototypes.

Eliminates gcc 4.9 warnings.

r287342 (by rodrigc):

Mark unused parameters to reduce gcc 4.9 warnings.

r287348 (by rodrigc):

Use correct function prototype for signal handler.

Eliminates gcc 4.9 warning.