Fix for parent window on review dialogs

When the reviewer class emits an alert, it was previously always
parented by the main window, but with arbitrary web views now supporting
the playback, this needed fixing.
TTS tag support for 'preset' attribute

Updates the template helper dialog to insert TTS tags with a 'preset'
attribute if the user has an active preset. Updates the reviewer to
understand this attribute and use it to look up the correct attributes
for a tag.