Added CommitDialogNumberOfPreviousMessages AppSettings (default value: 4), and using it in FormCommit (replaces the hard coded value).
Reformatted code.
Added editor for CommitDialogNumberOfPreviousMessages AppSetting to GitExtensionsSettingsPage.
'AutoScroll = true' for GitExtensionsSettingsPage.
Extracted CommitDialogSettingsPage from GitExtensionsSettingsPage.
Refactoring: Removed unused GitExtensionsSettingsPage.GetPageReference().
Realigned settings controls in GitExtensionsSettingsPage + refactoring (now using Dock=Top to align the group boxes).