Switch commoncpp2 to ucommon to solve dependency conflicts.

libccrtp was depending on commoncpp2, and have been replaced by a version
depending on ucommon as well.
diff --git a/jni/libccrtp/sources/src/ccrtp/crypto/skeinApi.h b/jni/libccrtp/sources/src/ccrtp/crypto/skeinApi.h
index cd07632..2f25073 100644
--- a/jni/libccrtp/sources/src/ccrtp/crypto/skeinApi.h
+++ b/jni/libccrtp/sources/src/ccrtp/crypto/skeinApi.h
@@ -78,8 +78,20 @@
  * 
  */
 
-#include <ccrtp/crypto/skein.h>
+#include <crypto/skein.h>
+
+#ifdef _MSC_VER
+typedef signed __int8 int8_t;
+typedef unsigned __int8 uint8_t;
+typedef signed __int16 int16_t;
+typedef unsigned __int16 uint16_t;
+typedef signed __int32 int32_t;
+typedef unsigned __int32 uint32_t;
+typedef signed __int64 int64_t;
+typedef unsigned __int64 uint64_t;
+#else
 #include <stdint.h>
+#endif
 
 #ifdef __cplusplus
 extern "C"