fix flipped image in Android

see: #44

Author: hunterk

jni/Android.mk

@@ -9,7 +9,7 @@ include $(CORE_DIR)/Makefile.common
 COREFLAGS := -ffast-math $(COREDEFINES) $(INCFLAGS)
 GIT_VERSION := " $(shell git rev-parse --short HEAD || echo unknown)"
 ifneq ($(GIT_VERSION)," unknown")
- COREFLAGS += -DGIT_VERSION=\"$(GIT_VERSION)\"
+ COREFLAGS += -DGIT_VERSION=\"$(GIT_VERSION)\" -DHAVE_OPENGLES=1
 endif
 
 include $(CLEAR_VARS)