o cf_define_symbol() -- it assigns a meaning to a symbol, bailing
out if it already has one.
o cf_find_symbol() -- finds symbol by name and creates it if not found.
Also modified filter/config.Y to make use of the first function.
- cfg_strcpy() -> cfg_strdup()
- mempool -> linpool, mp_* -> lp_* [to avoid confusion with memblock, mb_*]
Anyway, it might be better to stop ranting about names and do some *real* work.
o cfg_alloc(size) -- generic memory allocation
o cfg_allocu(size) -- unaligned memory allocation
o cfg_allocz(size) -- zeroed memory allocation
o cfg_strcpy(str) -- allocate a copy of a string
Also fixed a bug in lexing of string literals.
