add min and max dt support for example interface, add dump_period, fixed simulation time of interest vs end of simulation bug, fixed typos

added energy plot for U and W in the poisson curl operator, added example usage to Taylor-Green example

fixed symbolic codegen argument order, fixed example_utils opencl options, fixed OpenClTypegen repr, fixed autotuner caching problems.

Fix missing diagonal ghosts that were not set to NAN, causing nanmin and nanmax to fail on uninitialized memory, resulting in bad adaptive time step criteria computations.