Added all necessary BPY_extern.h include files to the .c files.

Updated the Make environment to point to the correct location. The include
paths were still pointing to source/blender/bpython/include while it should be
source/blender/python.
I did not encounter the build problems because I'm always working with the
autoconf build environment.

source/blender/src/space.c

@@ -130,6 +130,8 @@
 
 #include "BLO_readfile.h" /* for BLO_blendhandle_close */
 
+#include "BPY_extern.h"
+
 #include "mydevice.h"
 #include "blendef.h"
 #include "datatoc.h"