ThomasBrady

I'll squash this later, but for ease of reviewing, I [changed the semantics](https://github.com/stellar/stellar-core/pull/4178/commits/0b22c56a1057e1cc134fe3a39a59e329fee26217) of `LedgerKeyMeter` slightly: * If a key is not in the footprint of any transaction added to...

> Doesn't Tracy allow you to delete data before a certain point (or only select a specific timeframe)? You can discard the entire trace while it is being captured, but...

@SirTyson can you PTAL?

@SirTyson I had to rebase, can you re-enable automerge?

> we need multiple accounts because of the way transaction queues work, Ah, I see. `TransactionQueue::mAccountStates` has a map from `AccountID` to `AccountState`, which only contains at most one transaction...

Design / planning doc https://docs.google.com/document/d/1GRzHAO4_YrfanXqoVc1UDIMhUV10PFqIMQyOxlPOW_s/edit?usp=sharing cc @marta-lokhova / @anupsdf

Hey, the current plan is to skip signature verification and validity checks for all transaction types and to skip application for failed transactions, outlined [here](https://docs.google.com/document/d/19YgyNwmETBhL5tZUv0y1HS93ZeICTik3DObCDvsSyCM/edit#heading=h.oky5f9ion3uj). I have a branch with...

> I see [@ThomasBrady](https://github.com/ThomasBrady) . Yeah we definitely need some idea of potential saving for each part (like: is skipping crypto high impact) of this as it potentially creates a...