Moved Android specific logger to separate plugin.

This is mainly because the other parts of the existing android plugin
can not be built in the NDK (access to keystore and system properties are
not part of the stable NDK libraries).

src/libcharon/plugins/android_log/Makefile.am

@@ -0,0 +1,17 @@
+
+INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/libhydra \
+	-I$(top_srcdir)/src/libcharon
+
+AM_CFLAGS = -rdynamic
+
+if MONOLITHIC
+noinst_LTLIBRARIES = libstrongswan-android-log.la
+else
+plugin_LTLIBRARIES = libstrongswan-android-log.la
+endif
+
+libstrongswan_android_log_la_SOURCES = \
+	android_log_plugin.c android_log_plugin.h \
+	android_log_logger.c android_log_logger.h
+
+libstrongswan_android_log_la_LDFLAGS = -module -avoid-version