Adds support for Hipchat's V2 API by way of setting the version flag. V1 paths
should remain unchanged. A setVersion() method is provided for convenience in case
one does not want to override all of the default parameters.
As explained in its docblock, the validation function will fall back to
a simple strlen check if mb_strlen is not available. However, that very
specific case is not one that was deemed important to support, as anyone
using UTF-8 in their code, without having mbstring available will
probably have bigger problems to worry about.
Fixes#289
Adds a handler that is capable of sending notices into HipChat, the team communication system provided by Atlassian.
This is based on the PushoverHandler and built on top of the socketHandler.
The needed configuration is described in the docblock of the HipChatHandler file.
