* Implements ability to defer seed phrase backup to later
* Adds incremental-security.spec.js, including test dapp that sends signed tx with stand alone localhost provider
* Update metamask-responsive-ui for incremental account security changes
* Update backup-notification style and fix responsiveness of seed phrase screen
* Remove uneeded files from send-eth-with-private-key-test/
* Apply linguist flags in .gitattributes for send-eth-with-private-key-test/ethereumjs-tx.js
* Improve docs in controllers/onboarding.js
* Clean up metamask-extension/test/e2e/send-eth-with-private-key-test/index.html
* Remove unnecessary newlines in a couple first-time-flow/ files
* Fix import of backup-notification in home.component
* Fix git attrs file
* Add tests for ImportWithSeedPhrase#parseSeedPhrase
* Handle importing whitespace-only seed phrases
Fixes#6694
This changeset fixes our parsing of seed phrases during import to handle the
case where a user tries to import a seed phrase that consists solely of whitespace.
We no longer produce an error and instead treat it as an incorrect seed phrase.
* Handle importing more invalid seed phrases
