- Allows arbitrary length line continuation constructs in specs, but
probably the more useful side-effect is cleanly handling unterminated
macros and the like (instead of segfaulting) on large spec files,
there was a bug on this somewhere but cant find it atm.
- This also has a wee bit silly effect on the maximum macro expansion size:
after very long constructs the max expansion gets is bigger than
at the beginning of spec parse, but properly fixing the resizing wrt
macros is a different issue.
- Watch out for possible fallout from spec->line etc tracking, they
*seem* to be ok even with the potentially moving buffer location but...