Updated internals of ECOS regarding initialization.

Two subsequent calls of ECOS now produce exactly the same iterates.
This fix was needed to allow multiple calls to ECOS without running ecos_setup more than once.

This is useful for certain parametric problems, i.e. when the RHS of the inequalities Gx <= h
or equalities Ax=b change from one call to another.

Small other fixes regarding unused variables etc. in the tests.