Determine new issues

[pascalberger]

In case of a project containing some issues, we should determine which issues are caused by a specific pull request.

Approach:

• Store log files as artifacts on build system
• Check if a pull request buid
• Get target branch from pull request system
• Determine last successful build of target branch at time source branch was branched or earlier
• Retrieve log files from build system
• Parse old log files
• Compare log issues from old logfiles with current issues
• Filter issues reported to pull request system to issues not already available in the old logs
• Add column to issues report to mark new issues