browse.py: fix delay with multiple connections
browse.py: fix delay with multiple connections

When Firefox opens two TCP connections and sends a request over the
second connection, it is not processed until the first one is closed.
Use a threaded server to solve this issue. Tested with Python 2.7.15 and
3.6.5. (Also tested with 2.6, but that failed due to lack of argparse.)

Link: https://bugs.python.org/issue31639

bradking/ninja,Qix-/ninja,ndsol/subninja,atetubou/ninja,atetubou/ninja,mydongistiny/ninja,bradking/ninja,AoD314/ninja,Qix-/ninja,ninja-build/ninja,Qix-/ninja,ndsol/subninja,atetubou/ninja,martine/ninja,martine/ninja,bradking/ninja,ninja-build/ninja,nicolasdespres/ninja,maruel/ninja,bradking/ninja,iwadon/ninja,nicolasdespres/ninja,mydongistiny/ninja,nicolasdespres/ninja,maruel/ninja,nicolasdespres/ninja,iwadon/ninja,maruel/ninja,Qix-/ninja,AoD314/ninja,maruel/ninja,atetubou/ninja,martine/ninja,mydongistiny/ninja,ndsol/subninja,sgraham/ninja,iwadon/ninja,martine/ninja,sgraham/ninja,AoD314/ninja,ndsol/subninja,ninja-build/ninja,ninja-build/ninja,iwadon/ninja,sgraham/ninja,mydongistiny/ninja,sgraham/ninja,AoD314/ninja