osteosarc 0.13.3

Faster bundle builds (#82). Rebuilding openvax-v1 from cached reads takes 2.7 minutes and 1.4 GB instead of 31 minutes and 21 GB, and gives the same bundle, byte for byte.

• Selection reads only what it can choose from. osteosarc first reads every target's window from the extract's index, then keeps the templates found there, whole, and any a library names or pins.
• Each source is counted once, not once per member.
• Faster checksums. Record checksums are about twice as fast.
• select_fixtures(...).records holds, for a source whose members all pin exact records, only those records.

Additive: nothing is removed or renamed.