Py/RNA API: WITH_PYTHON_SAFETY

compile time option which enables extra safety checks.
since this is noticeably slower I rather not enable by default yet.

source/blender/python/SConscript

@@ -1,24 +1,37 @@
 #!/usr/bin/python
-Import ('env')
 
-sources = env.Glob('intern/*.c')
+# TODO, split into 2 files.
+
+Import ('env')
 
 incs = '. ../editors/include ../makesdna ../makesrna ../blenlib ../blenkernel ../nodes'
 incs += ' ../imbuf ../blenloader ../render/extern/include ../windowmanager'
 incs += ' #intern/guardedalloc #intern/memutil #extern/glew/include'
 incs += ' #intern/audaspace/intern ' + env['BF_PYTHON_INC']
 
+is_debug = (env['OURPLATFORM'] in ('win32-mingw', 'win32-vc','win64-vc') and env['BF_DEBUG'])
+
+# generic
 defs = []
 
+if is_debug:
+    defs.append('_DEBUG')
+
+sources = env.Glob('generic/*.c')
+env.BlenderLib( libname = 'bf_python_ext', sources = Split(sources), includes = Split(incs), defines = defs, libtype = ['core','player'], priority = [362,165]) # ketsji is 360
+
+
+# bpy
+defs = []
+
+if is_debug:
+    defs.append('_DEBUG')
+
+if env['WITH_BF_PYTHON_SAFETY']:
+    defs.append('WITH_PYTHON_SAFETY')
+
 if env['BF_BUILDINFO']:
     defs.append('BUILD_DATE')
 
-if env['OURPLATFORM'] in ('win32-mingw', 'win32-vc','win64-vc') and env['BF_DEBUG']:
-    defs.append('_DEBUG')
-
+sources = env.Glob('intern/*.c')
 env.BlenderLib( libname = 'bf_python', sources = Split(sources), includes = Split(incs), defines = defs, libtype = ['core','player'], priority = [361,160])
-
-
-# generic
-sources = env.Glob('generic/*.c')
-env.BlenderLib( libname = 'bf_python_ext', sources = Split(sources), includes = Split(incs), defines = defs, libtype = ['core','player'], priority = [362,165]) # ketsji is 360