Better TPSA print

[DavidSagan]

• The "I" column has got to go.
• Do not print coefficients whose magnitude is less than eps where eps is a global that users can set and whose default value is small (like 1e-10).

[mattsignorelli]

@DavidSagan Ok, take a look at the current format and let me know

[mattsignorelli]

One change could be to use the sparse monomial order indexing ( 1 0 1 would be 1=>1, 3=>1) for the exponents column. I think this might be a lot cleaner for when the GTPSA has a number of variables above say 10, or we could just default to it

[mattsignorelli]

Sparse monomial indexing added, printing also uses PrettyTables.jl which takes care of when it might go off the screen. I don't think I will add. the eps, because I'm hesitant to add a non constant global and there's some other reasons too we can discuss tomorrow. So the printing should be complete now

[mattsignorelli]

Sparse monomial format will be used for printing when nv + np > 6