Added splitLog mutation.

graph2/schema/types/Log.gql

@@ -122,6 +122,17 @@ input LogImportInput {
   data: String!
 }
 
+"""
+Input for splitLog mutation.
+"""
+input LogSplitInput {
+  "Log ID"
+  logId: String!
+
+  "After Post ID"
+  startPostId: String!
+}
+
 enum LogImporter {
   """
   mIRC-like: This importer parses logs that copied from mIRC posts without spaces.