Merge pull request #400 from sortega/fix_connection_status

Improve bitcoin connection status handling
Fix heisenbug in ConnectionActorTest
Add missing test cases to ConnectionActorTest
Merge pull request #401 from sortega/fix_connection_test

Fix connection test
Fix wrong rendering of menu bar on Windows platform
Merge pull request #402 from apoloval/bug/cf-154

Fix wrong rendering of menu bar on Windows platform