ActiveMQ: Added edit and resend message functionality

Implemented in form of an Angular shared service: "activeMQMessage". 
Please see if it's ok.


Resend button is enabled only if a single message is selected.
Clicking on resend bring the user to the composition page were custom Headers and body content are automatically prefilled.

Cover part of this request: #1391

![screenshot from 2014-07-10 16 41 51](https://cloud.githubusercontent.com/assets/1520602/3540295/a2f72764-0841-11e4-9ff1-6aeab77429a4.png)

![screenshot from 2014-07-10 16 46 23](https://cloud.githubusercontent.com/assets/1520602/3540300/a6bfda62-0841-11e4-83da-ff52f4424849.png)