Filter small numbers in GTAPWiNDC module

[mitchphillipson]

Issue

In the final output of the GTAPWiNDC module there are a large number of small numbers. These can be suppressed to restore the sparsity of the system. Currently the full model takes an unreasonable amount of time to solve.

Solution

Add a filtration step similar to other WiNDC modules.

[mitchphillipson]

Produced filter.gms which disposes of small values. Recalibrated zero profit identities. Still need to move the small market imbalances through to investment. Will do so shortly.