Configurable filtering

[toddinpal]

Currently the decision whether something is abusive or not is by looking for specific strings in the syslog message and if finding them, extracting the necessary information from the syslog message and reporting it. I suspect the easiest method to implement would be to allow entering a regex expression that if matches transforms the syslog message into an abuse report. So basically use a regex replacement string. Should probably allow including a way to specify what types of abuse, i.e., the AbuseIPDB categories, that the string matched.

[parakr]

Created PR with configurable regexp. Just tested and it seems to be working properly.