check that indices won't overflow, closes #212
check that indices won't overflow, closes #212

tfmorris/dedupe,pombredanne/dedupe,dedupeio/dedupe-examples,pombredanne/dedupe,dedupeio/dedupe,dedupeio/dedupe,neozhangthe1/dedupe,tfmorris/dedupe,davidkunio/dedupe,01-/dedupe,neozhangthe1/dedupe,davidkunio/dedupe,01-/dedupe,nmiranda/dedupe,datamade/dedupe,datamade/dedupe,nmiranda/dedupe