limit when the min/max size automatically applied

this prevents and issue where the solver attempts to size something
larger than it's computed max due to required constraints which overrule
strong constraints.
generalize this to non-container parents
add custom win32 extension for loading OEM icons
add support for raw argb32 images
tweak layout and styling
add static message box functions and pimpl

still need to document the main MessageBox enamldef