Add exploit for CVE-2014-6034

This is an exploit for a file upload vulnerability in ManageEngine OpManager and Social IT Plus. I've added the link to my advisory in my repo, and I will push a new commit here once the numbers from OSVDB and the full disclosure URL appear in their respective pages.

This module has been very well tested in both Windows and Linux, with almost all versions from 8.8 to 11.3 (the latest). Let me know if you have any questions or if there is anything you want me to change.
The algorithm is:
- try to upload the file in the default configuration
- wait up to SLEEP seconds (default 15) for a session to come back
- if it didn't came back, then we probably need to overwrite context.xml
- overwrite context.xml and try once. If that fails we return anyway.

So I don't see why you think it's forceful. At most it will make the user wait SLEEP seconds and bail.