stash changes before checkout new branches, in case there are some unstaged/uncommited changes

Author: WtfJoke

gitFunctions.py

@@ -90,4 +90,5 @@ def pushbranch(branchname):
 
     @staticmethod
     def checkout(branchname):
+        shell.execute("git stash")  # in case there are changes, stash them before checkout new branch
         shell.execute("git checkout " + branchname)