Travis: branch spec switch from white- to blacklist

Instead of only building master and master-1.2.x, we now build all
branches except master-2.0.x.

This allows users who fork the main repo and create feature branches
have them go through the build process
Travis: before_script use here-doc for apache config

Use bash instead of sh
Travis: before_script use here-doc for bootstrap
Travis: before_script improve mantisbt parameters setting

Instead of hardcoding the http query string directly in the cURL call,
we now build it from an associative array, which makes maintenance and
addition of new install parameters more easy.
Travis: before_script refactor db setup
Travis: before_script set crypto through installer
Travis: before_script use variable for hostname
Travis: before_script added tracing

Added some echo statements and separators in the output to make it
easier to see in the logs where things went wrong in case of failure.
Travis: before_script exit 1 in case of errors
Travis: improvements to before_script
Documentation: added Entity Relationship Diagram

Porting 1.2 diagram to master, applied schema changes up to 189.
Documentation: added ERD to developers manual
Revised ERD readme file

- updated Editing Recommendation
- Udate Documentation instructions