[TASK] Refactor error handler

The error handler is completely refactored so that user and
kernel part are cleanly separated. An implementation using
shared buffers and local variables is included. The files
are adopted to the new directory structure.

Change-Id: Ia33abe20c9d8d232a2bd3c1b77545456524c84eb
Reviewed-on: http://brateggevoat1/gerrit/402
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Joerg Zelenka <joerg.zelenka@br-automation.com>
Reviewed-by: Josef Baumgartner <josef.baumgartner@br-automation.com>
[TASK] Rework documentation

- Create new documentation directory structure
- Convert text files into markdown files
- Add doxygen files

Change-Id: I1cbb388fb1ffde872fc46eaf67b92a3700e42592
Reviewed-on: http://brateggevoat1/gerrit/428
Tested-by: Jenkins <jenkins@brateggevoat1.br-automation.co.at>
Reviewed-by: Wolfgang Seiss <wolfgang.seiss@br-automation.com>
Reviewed-by: Josef Baumgartner <josef.baumgartner@br-automation.com>