Implemented connection pooling in vrtManager/connection.py:
  * connections are shared among threads (not processes)
  * settings LIBVIRT_KEEPALIVE_INTERVAL and LIBVIRT_KEEPALIVE_COUNT added to control the clientside keepalive protocol
  * one connection per host will be created and used as long as it is alive
add new settings and explanation to settings.py and local_settings.py.example
remove socket host active check as it leads to weird messages in auth.log (at least for ssh connections). Connection error messages should be enough to determine what went wrong.
In the future it may also be possible to set "connection failed" based on the last error code returned by libvirt.
fix pep8
Fix #392
add unsafe parameter to migrate
Merge branch 'connection-pooling-pr' of git://github.com/myvision-de/webvirtmgr into myvision-de-connection-pooling-pr
Fix docs
Fix connection
Temporary fix for libvirt > libvirt-0.10.2-41
Merge pull request #397 from winstona/master

add unsafe parameter to migrate
Fix #398
Rebuilded host_is_up method (unuseful when connection is lost)
Fix pep8 and remove default Metadata
Fix pep8
Responsive design
fix table on create page
check if returned value is an array (fixes NonType object is unsubscriptable)
fix typo in instance/views.py
fixes TypeError: tostring() got an unexpected keyword argument 'method'