fix most sign and variable initialization warnings

Change-Id: I56e08db791152a9c95fc0d16bc75b702e403274d
diff --git a/Android.mk b/Android.mk
index bf7bd02..fcefe56 100644
--- a/Android.mk
+++ b/Android.mk
@@ -9,6 +9,7 @@
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := android/regex/regex.c
 LOCAL_C_INCLUDES := $(BB_PATH)/android/regex
+LOCAL_CFLAGS := -Wno-sign-compare
 LOCAL_MODULE := libclearsilverregex
 include $(BUILD_STATIC_LIBRARY)