Added path customization to iptables and ip6tables
Corrected added path customization to iptables and ip6tables
Fixed direction in default HFSC filter
 Some PEP8 suggested by PyCharm
Fixed rate and ceil checking
Merge pull request #1 from backslash7/master

Reasonable and wanted changes, thanks! I did it for one company, but tests showed me, Linux is much slower than Router OS on RouterBoard. You will be first who will use this.