More types of searches

[kchall]

Allow same / different searches (e.g., is hand 1 the same as hand 2? is config 1 the same as config 2? find all signs where hand 1 matches hand 1 of sign X...).

This can largely be run like the IRR script, but "within" a corpus; users should similarly be given the option to specifically "collapse" particular values as "the same" (e.g., [e] and [E]).

Also allow searches to specify whether signs are one-handed or two-handed.