Check for inofficial patches

[widhalmt]

We should check if something was changed in cleartext files. Namely Icinga Web code or Icinga Web modules.

The first way that comes to mind is shipping Diagnostics with a file full of checksums for different versions of supported projects. If they differ we should throw an anomaly.

Wild idea:

• Have a directory shipped with diagnostics
• In this is a "master checksum file" which holds checksums. One for every version of a project. To check it, tar the most important directories and pipe the tarfile into a hash function.
• If it differs, there could be a separate file for every version of every supported project. This way we could easily determine where a change has happened