Add multiprocessing freeze support to allow plugins to use multiprocessing.

Author: hsorby

src/mapclient/application.py

@@ -19,6 +19,7 @@
     along with MAP Client.  If not, see <http://www.gnu.org/licenses/>..
 """
 import json
+import multiprocessing
 import os
 import shutil
 import sys
@@ -523,4 +524,5 @@ def main():
 
 
 if __name__ == '__main__':
+    multiprocessing.freeze_support()
     main()