- Moved yang patch code to new files restconf_methods_patch.[ch]

- Started modifying patch code to style guidelines
- Made patch test independent of example
- Added developers style guidelines

apps/restconf/restconf_err.c

@@ -265,6 +265,7 @@ api_return_err(clicon_handle h,
 	goto done;
     switch (media){
     case YANG_DATA_XML:
+    case YANG_PATCH_XML:
 	clicon_debug(1, "%s code:%d", __FUNCTION__, code);
 	if (pretty){
 	    cprintf(cb, "    <errors xmlns=\"urn:ietf:params:xml:ns:yang:ietf-restconf\">\n");
@@ -280,6 +281,7 @@ api_return_err(clicon_handle h,
 	}
 	break;
     case YANG_DATA_JSON:
+    case YANG_PATCH_JSON:
 	clicon_debug(1, "%s code:%d", __FUNCTION__, code);
 	if (pretty){
 	    cprintf(cb, "{\n\"ietf-restconf:errors\" : ");