Modifications for v1.3.0 since v1.2.2

Added (partial) Python wrapper highspy
Highs::setSolution can now be used to give a solution to the simplex solver (#775)
Highs::addVar; Highs::addVars; Highs::deleteVars(Interval/set/mask) introduced for more natural modelling
logHeader now written as first output, even when using libraries (#784)
Highs::presolve and Highs::postsolve completed
Highs::resetGlobalScheduler added to reset the global scheduler
write_solution_style option modified:
- "Old" HiGHS raw solution style now indicated by value kSolutionStyleOldRaw = -1
- Raw and pretty solution formats for Glpsol now indicated by values kSolutionStyleGlpsolRaw = 2 and kSolutionStyleGlpsolPretty = 3
Many minor fixes handling marginal LP fle behaviour
Highs::crossover completed (#815)
scaled_model_status_ removed from Highs (#814)
Major revisions of CMake build system

Planned modifications for v1.3.0