Timestamp in new keys' filename

[gavofyork]

The filename of newly created keys should include a timestamp. Consider also placing the timestamp in the metadata.

[gavofyork]

Fixed in #1700.

[A2be]

It a bit hard for me to tell the specifics of what you did here. Looks like date is included, but what format, etc.?

In my view, best would be to

1. have Parity exactly match the keystore filename used in the de facto standard geth (largest adoption as of early July 2016), and to
2. also update the (de jure?) web3 spec at https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition so that all implementations of Ethereum Node software might be encouraged to use a similar (or identical) keystore naming standard for their keystore files.

Rationale : better UX for the uncommon, but not rare, occurrence where humans are actually looking at their keystore keys manually in a file manager, and the keys of various accounts were created by different Ethereum Node programs. In short, better for the Ethereum ecosphere long term to make user experience easier with long-forgotten keys stored on various odd digital storage devices.