Update helpers

[EleventyJeeves]

Add repeated regex + helpful plugin methods to helpers Source - http://chat.stackoverflow.com/transcript/message/34819064#34819064

[DaveRandom]

@JayPHP don't suppose you remember what you referring to here?

[JayPHP]

@DaveRandom regex to detect pings and valid chat URL's are defined and used throughout a lot of plugins and inbuilts - IIRC, the plan was to move common regex into a helper + methods for removing pings, resolving message text from URL etc..