WebFrontend: Add a link on the recordings screen for a future options menu. Doesn't actually do anything yet.
HTTPServer: Allow scripts served by master backend to access the Frontend webserver. The Cross Origin Resource Sharing standard.
Services API: Fix a few endpoints which should have been POST only.

RFC 2616 states "In particular, the convention has been established
that the GET and HEAD methods SHOULD NOT have the significance of
taking an action other than retrieval. These methods ought to be
considered 'safe'."

In other words, any endpoint which alters data or which triggers any
action such as starting video playback, sending notifications etc
should use POST. These are things that should not be triggered by
accident.
Replace a few instances of allocation on the heap when the stack would be better.
WebFrontend: Use POST for Frontend/PlayRecording request.