I made a proposal to have "bounty" transactions crafted that would incentive miners to pick up someone's stale transaction.

Possibly better than re-sending and starting a "double spend" war.

Proposal: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-July/009304.html
PrettyPrint: https://github.com/d4n13/bips/blob/master/bip-00nn.mediawiki