Fixed issue with Stop Server button (#273)

Button now cycles between "Stop Server" and "Start Server"
depending on whether the server is actually on or off.
Merge pull request #274 from nkait/stopserverfix

Fix #273 issue with Stop Server button
pyqt4.7.3
remove print line
Merge pull request #280 from hosi-mo/fix/pyqt4.7.3

Fix #281 - Only show placeholder text if PyQt supports it
Disable Controller Server start button when no passphrase given.

Fix for #278 issue for Controller Server start button.
Merge pull request #286 from cabernal/server-start-button-enablement

Fix #278 Passphrase required to start server