What changed in EDuke32, build by build

- Add declarations of C functions to defs.ilua, names to dynsymlist, fix typo in con_lang.lua, ffi.string() calls in control.lua - Assert that G_LastMapInfoIndex() is always called with ud.last_level >= 1. (A stricter requirement than necessary to prevent follow-up oob accesses, but logically the most meaningful.) - In G_PrintParTime() and G_PrintDesignerTime(), return "<invalid>" if the above does not hold. This can happen from EVENT_NEWGAME, for example. Add a test to lunatic/test/qgetsysstr.con. DONT_BUILD.

Previously, the C function clipmove() returned negative values when hit a wall (32768+wallnum) or sprite (49152+spritenum) because internally, these values were encoded into a *signed* 16-bit integer. This made no difference to C code using it, since it always proceeded by bit checks, but was inconsistent with documentation on CON 'clipmove' on the wiki. The following commands are affected too, since they use the value returned by clipmove(): 'clipmovenoslide', 'movesprite'. Also, the value of actor[].movflag ('htmovflag' from CON). Also, fix 'clipmove*' in LunaCON and add lunatic/test/checknearwall.con as an example of how to implement a being-close-to-a-wall checker as requested in http://forums.duke4.net/topic/7869-determining-closeness-to-a-wall/