Created skeleton files for Bugzilla online plugin

The skeleton files based on offline version of plugin.
Added Apache XML-RPC client libraries, created Bugzilla client skeleton and XML-RPC client which handle cookies. Added username and password fields to configuration dialog.
Added license informations
Added comments for clarification and replaced concrete parameter type with interface

Replaced HashMap with Map
Extracted method which add cookies to request
Removed absolute path to the sources of the library Apache XML-RPC
Added BugzillaOnlineXmlRpcClient integration tests
Added license and author informations
Merge branch 'bugzilla_online_plugin_feature' into dev