Umbra Modules update + Ransomware module

Change-log

Incorporated the so called Umbra Modules:

• Umbra modules: malware-like extensions for Umbra which can be triggered via the Umbra Injector.
• The rootkit backdoor now listens for the new injector requests accordingly.

Ransom: A ransomware-like module

• New Umbra Module "Ransom", a trivial ransomware program using a simple (very bad) encryption algorithm.
• Ransom can be used to encrypt or decrypt a whole directory (recursively, including sub directories) remotely.
• Encrypted files appear as .ubr files.

Other changes

• Added a script for installing Umbra and configuring the environment.
• New explanatory gifs on the README and updated other parts.
• Minor fixes.