Cleanup options

[vogler]

There are 32 'experimental' options. Maybe those could be better classified or cleaned up.
The number of experimental options should be kept at a minimum.
Todo:

• Introduce additional categories:
  • witness
  • solver
  • context
  • incremental
  • output
• Sort experimental options into the categories
• Rename defaults.ml to options.ml
• Finalize options, so that they cannot be mutated after the solver started
• ana.warnings is used
• warnstyle only refers to race warnings

Related #192

[michael-schwarz]

@sim642: What is the state of dbg.test.domain? Right now it fails right away with

domain testing analysis...: PathSensitive2(MCP2 context hashconsed) lifted hashconsed
About to crash! (:-1)
Fatal error: exception Failure("HConsed lifted PathSensitive (Set ([expRelation:(Unit), mallocWrapper:(lifted proglines), base:(value domain * array partitioning deps * P), threadid:(Thread), threadflag:(MT mode), escape:(top or Set (variables)), mutex:(Reversed (top or Set (Normal Lvals * booleans)))])): no arbitrary")

Do we want this option to do domain testing when running on a single program? If yes we should aim to fix it?
Or is this superfluous since we introduced the make domaintest target?