Reorganize CrySL Architecture

[AnakinRaW]

As discussed in today's meeting:

• Perform a relabeling fro CrypSL to CrySL java source files
• Extract and move (where possible) CrySL specific code to CrySL Repo (e.g.: such as CrySLRulesetSelector, etc.)
• Move relevant constants/enums (like the CrySL source file ending) into a separate file

In edit for my suggestion about to referencing CrySL in this Repo: I didn't look carefully enough what exactly was referenced. I was under the assumption that this repo depends on the Ruleset Repo. As this obviously is not the case my comment becomes obsolete. Depending on the CrySL Engine of course makes sense. I'd still agree however to minimize the referenced code basis by splitting the CrySL-Repo into more independent projects