MP1-4231 : Changes to support plugins as screensavers
MP1-4231 : Add new class to share plugin loading, so as not to duplicate effort
MP1-4231 : Clean up code formatting
MP1-4246 : Fix null reference when refresh SetupTV Form.
Merge remote-tracking branch 'remotes/origin/MP1-4246-BUG-Fix_null_reference_when_refreshing_SetupTV_Form'
MP1-4155: correct processing of '+' in encoded parameter value
MP1-4231 : Fix an index out of range bug
Merge remote-tracking branch 'remotes/upstream/MP1-4231-FEAT-Allow_plugins_as_Screensavers' into 1.5.0Fork

Conflicts:
	mediaportal/Configuration/MediaPortal.Configuration.csproj
	mediaportal/Configuration/Sections/PluginsNew.cs
Merge remote-tracking branch 'remotes/upstream/master' into 1.5.0Fork
Merge remote-tracking branch 'remotes/upstream/MP1-4155-FEAT-Merge_of_IPTV_filter_and_MediaPortal_Url_Source_Splitter' into 1.5.0Fork