Bugfix and some features for context menus

* Fixed a bug: exception when opening context menu that offers a choice
of preset options (like side) for any numeric value that contains an
expression
* HullID context menu should now be nested to prevent insanely tall menu
that is clunky and hard to navigate
* Chosen value should now be selected by default when opening a context
menu that offers "input value" option as well as preset choice of
options
NOTE: This was for some reason manually disabled, and I do not know for
what purpose. It looks like it's better when it's enabled.
If someone finds out why this is actually a bad change for some reason,
please contact me (starsabre@gmail.com) and I'll revert it.