Added code for resizing of the recent-changes-window

Added new Class "SparkleRecentChangesWindow"
Added new Class "WPFChromeExtensions" for customizing minimize and
maximize-buttons.
Introduced custom file for SparkleScriptingObject.
Created parameterless constructor for sparklespinner (can now be used in
XAML) and added check for designmode.
Added code to to event-log.html to avoid showing scrollbars in
webbrowser-control.