Remove conditional dependency on receive patterns

If message A was delivered to process P before message B, then there should
be a race only if the patterns in the receive that gets A can also match B.
Unfortunately this is a 'conditional dependency' (we don't know the patterns
when A or B is delivered) and cannot be handled correctly when planning more
interleavings. So this feature is removed for the time being.
Option to generate DOT file (closes #11)
Cleanup debug printouts
Fix bug in symbolic children name numbers
Disable application_controller hijacking (re-opens #2)

Application controller has inner state that is not guaranteed to be restored
after completion of an interleaving and needs to be checked.
Merge pull request #27 from aronisstav/ignore_receive_patterns

Ignore receive patterns