ACSL to TriCera predicate translation

[woosh]

Currently Saida is not capable of translating ACSL predicates into the TriCera counterpart. In real-world cases it will be very useful if Saida supports translation of ACSL predicates into TriCera predicates.

Outline:

• Create predicate ptest
• Create predicate collector visitor
• Translate ACSL predicate to TriCera - no support for axiomatic predicates
• Add support for predicates in requires/ensures.