Fixup pairparsevalue signature (should return bool)

Fix places which assumed because it returned an int, it would return a negative integer to indicate failure.
Skip the entry if expansion fails for one of the check items
char buffer[sizeof(check->vp_strvalue)];

Guessing we don't want a 4 or 8 byte buffer...
If pairparsevalue gets called on a regex pair, we DON'T attempt to parse the value, and instead copy the string value over verbatim.