hash table CHANGE new debug category for hash table changes

Fixes #963
diff --git a/src/libyang.h.in b/src/libyang.h.in
index d0cd8d7..8f51c1d 100644
--- a/src/libyang.h.in
+++ b/src/libyang.h.in
@@ -1916,6 +1916,7 @@
 #define LY_LDGXPATH 0x08 /**< XPath parsing end evaluation. */
 #define LY_LDGDIFF  0x10 /**< Diff processing and creation. */
 #define LY_LDGAPI   0x20 /**< API tracing. */
+#define LY_LDGHASH  0x40 /**< Hash table modifications. */
 
 /**
  * @}