#323 Ignore/Blacklist for catalog

[Gerd Katzenbeisser]

It would be great to have a ignore function for each indexed folder (like a .gitignore or .hgignore) to block specific files being indexed.

Currently the only option is to specify a whitelist of filetypes. In my case I have an application folder on the network I want in my catalog. But one application collides with a local appliction. So I don't want this specific application on the network folder to be in the catalog.

Another usecase is: In search results I often get applications twice (x86 and x64) versions. But I only want the x64 versions and would like to blacklist x32.exe and x86.exe