Add ProcessMaker Open Source Authenticated PHP Code Execution

Add ProcessMaker Open Source Authenticated PHP Code Execution exploit module.

Description:
ProcessMaker is an open source, workflow management software suite, which
includes tools to automate your workflow, design forms, create documents, assign
roles and users, create routing rules, and map an individual process quickly and
easily. It's relatively lightweight and doesn't require any kind of installation
on the client computer.

* Homepage: http://www.processmaker.com/
* Source: http://sourceforge.net/projects/processmaker/
* VM: http://www.turnkeylinux.org/processmaker
* Tested on:
  * ProcessMaker versions 2.5.1, 2.5.0, 2.0.23 (Windows XP SP3)
  * ProcessMaker version 2.0.45 (Debian Linux)

![ProcessMaker Open Source Authenticated PHP Code Execution](https://f.cloud.github.com/assets/434827/1428320/fef1ef22-40a0-11e3-962b-8554135a4e9d.png)