Check -- Option for matrixFactorization

Makes matrixFactorization perform various checks as it computes.

Functions with optional argument named Check:

• EisenbudShamashTotal(...,Check=>...) -- see EisenbudShamashTotal -- Precursor complex of total Ext
• layeredResolution(...,Check=>...) -- see layeredResolution -- layered finite and infinite layered resolutions of CM modules
• makeFiniteResolutionCodim2(...,Check=>...) -- see makeFiniteResolutionCodim2 -- Maps associated to the finite resolution of a high syzygy module in codim 2
• matrixFactorization(...,Check=>...) -- see matrixFactorization -- Maps in a higher codimension matrix factorization
• newExt(...,Check=>...) -- see newExt -- Global Ext for modules over a complete Intersection