Added option to output gnuplot commands
Preliminary version of PPT (pseudo parallel tempering)
Adjusted pptb exchange feedback mechanism
Change PPT iteration count to be more meaningful
pptc: Lagrangian method for estimating probability function
Fix pptc's feedback (so g doesn't get clipped at 0 so much,
and don't use final (g0+g1)/2 when g1 may be wrong)
Replaced target final prob method with minimise-lagrangian method
Revert "Replaced target final prob method with minimise-lagrangian method"

This reverts commit 05d84257cfd826731d68fbda0b74562e42734f61.
-m27: Exchange history, option (currently off) to sort rather than exchange, upd=0 meaning infinity, submode 3 meaning simple geometric pp[] without aiming for the given ttp
Minor (print levels, adding PPT to makegraphs2)