#370 Generalized CIF to Supremica precondition checks to reusable checks.

Model walkers:

• ModelWalkerGenerator now also generates composite model walkers.
• Removed unused rootClassName argument/variable from ModelWalkerGenerator.

EMF code generators

• Removed 'v1x0x0' from JavaDoc.
• Small improvements and alignments for EMF code generators.

CIF (pre)condition checkers:

• Added generic CIF (pre)condition check(er) functionality.
• Added various preconditions checks. Based on the ones used by CIF to Supremica. Some more general checks as well.
• Change CifToSupremicaPreChecker to use generic checker, and updated CIF to Supremica expected test output. Other checkers to be done in separate branches.

CIF common:

• Added CifTextUtils.hasName/getNamedSelfOrAncestor.

I recommend reviewing per commit.

Addresses #370 (closed)