Upgrade mapper/router to new IR

[pablolh]

A long journey through the mapper

• New IR in place of old IR
• New DDG is used in place of old scheduler
• Various code improvements (e.g. return result instead of modify reference parameter, paths as lists)
• FreeCycle stores its map as an association list mapping new IR references to uints
• Had to implement "remaining" path length in new DDG. Seems there is already some sort of implementation of criticality but those require scheduling to run first
• Random number generation is seeded with constant seed

Note: the code is still quite untested. I've done my best to check that the program works as expected, but given the number of options and complexity of the code, only proper unit testing for each part and class (e.g. AlterTest, PastTest) can give a good guarantee of functionality. This would take quite some time to implement.

I have updated the docs to signal when an option is only valid when using the minextend/minextendrc route heuristics.

[pablolh]

There is a new test map_test.cc that is not really a unit test but gives some guarantee as to preservation of the semantics of the circuit. It's quite basic though. There is potentially more work to do on this mapper/router but let's not spend too much time on this since there are more urgent matters. namely removing the old IR

My work ethics tell me to signal that the decomposition to primitives is quite untested since I haven't set mapdecompositionrulepattern in any test (so the old tests now don't make use of the finer-grained scheduling obtained by decomposing to primitives) and I haven't updated the cclight platform configurations to use new-style decompositions.

See also #482

[jvansomeren]

We first have to filter the issues out of these conversations before closing this pull request, since they are lost otherwise. I started by creating the issues. Still must fill them with the applicable conversations above and then resolve those latter.

[pablolh]

New change is coming up soon