Development tools

Based on the PR #285 this PR contains development tools which should ease adding user-agents to the tests as well as comparing large lists of user-agents.
The use of the tools is described in devel/README.md.
To allow a determination of the regex line in regexes.yaml a slight change to the js-parser is needed.

This PR has the following goals:
* Ease adding testcases for the different parsers.
* Ease adaptation of regular expressions in the regexes.yaml file.
* Generate visibility of changes to the regexes.yaml file for a contributor
* Generate visibility of bad user-agent matches for a contributor such allowing him to change the regexes.yaml file as well as changing the testcases accordingly.