Encrypt and compress the MiniDump in memory before touching disk

[hfz1337]

• [x] Added some refactoring.
• [x] Added a callback function for MiniDump in order to encrypt the dump in memory. This solves the issue where the dump is flagged as Trojan:Win32/LsassDump.A. With this approach we make sure that the real dump never touches the disk.
• [x] Added randomization to the filename.

The user will have to gunzip and decrypt the dump before it can be used (the current encryption scheme is a simple memfrob, but it can be customized by the user).