Drop maintainer mode - enable by default

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Rename INCLUDES to AM_CPPFLAGS

src/Makefile.am:22: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Merge build fixes from Peter Hutterer.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>