Move all methods and tests related to complex numbers from PMMatrix and PMVector into Math-Complex package

[olekscode]

This would remove the coupling between Collections and Complex numbers (which live in a separate package).

Some (perhaps not all) examples include:

• PMVector >> isReal
• PMMatrix >> isReal
• PMVectorTest >> testIsRealOnComplexVector
• PMVectorTest >> testIsRealOnRealVector
• PMMatrixTest >> testIsRealOnComplexMatrix
• PMMatrixTest >> testIsRealOnRealMatrix

Those methods can apply both to real and complex matrices. But implementation depends on PMComplex, so I don't know what to do there:

• PMMatrix >> isHermitian
• PMMatrix >> isNegativeDefinite
• PMMatrix >> isNegativeSemiDefinite
• PMMatrix >> isPositiveDefinite
• PMMatrix >> isPositiveSemiDefinite

[hemalvarambhia]

One thing worth noting is that matrices are defined over Fields (set and the binary operation +, *). Perhaps that is the worth exploring in answer to the messages isHermitian etc.

[jecisc]

First step in: #292