New feature: full treatment of crystallographic data and experimental techniques

This is quite a big patch solving issues #101 and #102. Also some methods are deprecated due to the new additions.

An important addition is an extensive test of PDB vs mmCIF parsing in the integrationtest module. It takes very long to run (more than 1 hour) and thus it is excluded from testing in the main pom.xml. It will only run if called explicitly with a `mvn -Dtest=` command. I've found this kind of testing to be very useful for me in the https://github.com/eppic-team/owl project. In fact using it I've already found a few issues that I need to submit.