Upgrade to expat 2.1.0.

From http://www.libexpat.org/:

Release 2.1.0 includes security & other bug fixes, new features, and updated build support.

Security fixes

* Memory leak in poolGrow (CVE-2012-1148)
* Resource leak in readfilemap.c (CVE-2012-1147)
* Hash DOS attack (CVE-2012-0876)
* Buffer over-read and crash in big2_toUtf8 (CVE-2009-3560)
* Parser crash with special UTF-8 sequences (CVE-2009-3270)

New features

* Added function XML_SetHashSalt that allows setting an initial value (salt) for hash calculations (part of the fix for bug 3496608).
* When compiled with XML_ATTR_INFO defined, adds new API member XML_GetAttributeInfo() that allows retrieving the byte offsets for attribute names and values (patch 3446384).
* Added CMake build system (bug 2990652, patch 3312568).
* Added run-benchmark target to Makefile.in - relies on testdata module present in the same relative location as in the repository.

Bug fixes

* Harmful XML_ParserCreateNS suggestion (1742315)
* CVE-2012-1147 - Resource leak in readfilemap.c (2895533)
* Expat build fails on linux-amd64 with gcc version>=4.1 -O3 (1785430)
* Build modifications using autoreconf instead of buildconf.sh (1983953, 2517952, 2517962, 2649838)
* OBJEXT and EXEEXT support while building (2815947, 2884086)
* CVE-2009-3720 - Parser crash with special UTF-8 sequences (1990430)
* xmlwf should return non-zero exit status if not well-formed (2517938)
* Wrong statement about XMLDecl in xmlwf.1 and xmlwf.sgml (2517946)
* Dangling positionPtr after error (2855609)
* CVE-2009-3560 - Buffer over-read and crash in big2_toUtf8() (2894085)
* CVE-2012-1148 - Memory leak in poolGrow (2958794)
* UNEXPECTED_STATE with a trailing "%" in entity value (3010819)
* Unitialized memory returned from XML_Parse (3206497)
* make check fails on mingw-w64 (87849)

Change-Id: Ieb663fdfea82119918e245a714af533b58e0f7f5
diff --git a/Android.mk b/Android.mk
index e62a069..e81c976 100644
--- a/Android.mk
+++ b/Android.mk
@@ -8,7 +8,12 @@
 	lib/xmlrole.c \
 	lib/xmltok.c
 
-common_CFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes -fexceptions -DHAVE_EXPAT_CONFIG_H
+common_CFLAGS := \
+    -Wall \
+    -Wmissing-prototypes -Wstrict-prototypes \
+    -Wno-unused-parameter -Wno-missing-field-initializers \
+    -fexceptions \
+    -DHAVE_EXPAT_CONFIG_H
 
 common_C_INCLUDES += \
 	$(LOCAL_PATH)/lib
@@ -32,6 +37,7 @@
 endif
 
 LOCAL_MODULE:= libexpat
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE_TAGS := optional
 
 include $(BUILD_HOST_STATIC_LIBRARY)
@@ -48,6 +54,7 @@
 endif
 
 LOCAL_MODULE:= libexpat
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE_TAGS := optional
 LOCAL_COPY_HEADERS_TO := $(common_COPY_HEADERS_TO)
 LOCAL_COPY_HEADERS := $(common_COPY_HEADERS)
@@ -71,6 +78,7 @@
 LOCAL_C_INCLUDES += $(common_C_INCLUDES)
 
 LOCAL_MODULE:= libexpat_static
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE_TAGS := optional
 
 include $(BUILD_STATIC_LIBRARY)
@@ -88,6 +96,7 @@
 LOCAL_C_INCLUDES += $(common_C_INCLUDES)
 
 LOCAL_MODULE:= libexpat
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE_TAGS := optional
 LOCAL_COPY_HEADERS_TO := $(common_COPY_HEADERS_TO)
 LOCAL_COPY_HEADERS := $(common_COPY_HEADERS)