automatic documentation update
Eliminated Mapping in diag(MX), #616
Added sp_unit for generating the sparsity pattern of a unit vector
Corrected bug in ConstantMX
Added chain-mass example
Zero-based printing of input/output indices, consistent with the getting and setting
Refactoring of UnaryMX with support for simplification, #627
Refactoring of BinaryMX with support for simplification, #627
More MX simplificaton, #627
Corrected (old) bug in MX simplification, #627
Merge branch 'debug_mx' into issue_616