* added a CVAR that sets how localizable graphics need to be dealt with.
* pass the substitution string to OkForLocalization so that proper checks can be performed.
* increased item spacing on Doom's list menus to 18 from 16 pixels, because otherwise the diacritic letters would not fit. 20 would have been more ideal but 18 was the limit without compromising its visual style
* added a second text-only main menu because here the spacing cannot be changed. Doing so would render any single-patch main menu non-functional. So here the rules are that if substitution takes place, it will swap out the entire menu class.
* fixed some issues with the summary screen's "entering" and "finished" graphics.
- Implement page string names for dialog lumps
- Create special new GZDoom name space for ZSDF
- add usdf_gzdoom spec document
- fixed: restored original behavior with negative conversation id's for the original strife dialog lumps
- reposition the binary strife fix in a more appropriate location
- add compatibility fix for negative numbers in responses in USDF/ZSDF (don't know if it's actually necessary)
