ids-functions.pl: Rework oinkmaster() function.

ids-functions.pl: Rework oinkmaster() function.

Rework the function to work with the latest changes and multiple
providers.

The function now does the following:

* Extract the stored rules tarballs for all enabled providers.
* Copy rules files for enabled providers which provide plain files.
* Still calls oinkmaster to set up the rules and modify them.
* Calls the merge functions for classification and sid to msg files.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>