fixes #1783 - Default template set incorrect snippet names if snippet name uses underscore

removed depericiated warnings

fixes #1180 - db migration may fail because of missing logger

Fixes #378 - Adds support for multiple configuration templates

Configuration templates (Kickstart, preseed, syslinux, gpxe etc) can now
be saved in the database directly.

Each template is associated with valid operating systems (unless if its a
snippet which can rendered via all other templates) and a possible...