don't combine when we don't demand complete albums

[canidae]

it is pointless combining groups if we don't demand complete albums, because all files will be looked up anyways. the problem here is that the class that combines groups (Locutus) doesn't know whether we demand complete albums or not. possible solutions:

• document that it's pointless and let the user sort it out
• make the variable that denotes whether we demand complete albums public in Matcher or make a getter
• fetch the setting in Locutus as well as Matcher

we might want to look more into this. currently we won't lookup files if we've compared the file with an album and the score is high enough when we demand complete albums. if we don't demand complete albums then we'll always look up the file.
is this sane? i think it is, the "only save complete albums" thingy sort of is the difference between "album matching" and "single file matching". it's possible this should be documented well somehow.