Improved typing

Improved typing and added an optional `callback` argument to `sim.sub…

…mit()`. This allows a Callable to be passed to `sim.submit()` that is called after the simulation files are written.

Update version to 1.3.6 and added versions notes

improvements to `set_dv`, `ui.messages.show_message` now respects mes…

…sage threshold

Small change to `write_bin_file`

refactoring and minor feature enhancements

minor bug fixes

minor bug fixes

changed version number

new features, bug fixes, refactoring