Unable to delete contact from contact list.

[tmashuang]

1. Add a new contact with any name and a valid address,
2. Go to contact list, select contact, Edit, Delete Account

Bug: Delete Account will not remove contact from the list. Any following actions; editing contact, going to main screen, etc. shows infinite loading spinner

Background Errors right when clicking Delete Account:

metamask-controller.js:1393 TypeError: Cannot read property 'toLowerCase' of undefined
    at Object.exports.toChecksumAddress (index.js:388)
    at AddressBookController.delete (AddressBookController.js:37)
    at Proto.apply (index.js:123)
    at Proto.handle (index.js:99)
    at dnode.handle (dnode.js:140)
    at dnode.write (dnode.js:128)
    at Substream.ondata (_stream_readable.js:612)
    at emitOne (events.js:106)
    at Substream.emit (events.js:184)
    at addChunk (_stream_readable.js:284)
    at readableAddChunk (_stream_readable.js:271)
    at Substream.Readable.push (_stream_readable.js:238)
    at ObjectMultiplex._write (index.js:68)
    at doWrite (_stream_writable.js:406)
    at writeOrBuffer (_stream_writable.js:395)
    at ObjectMultiplex.Writable.write (_stream_writable.js:322)
    at PortDuplexStream.ondata (_stream_readable.js:619)
    at emitOne (events.js:106)
    at PortDuplexStream.emit (events.js:184)
    at addChunk (_stream_readable.js:291)
    at readableAddChunk (_stream_readable.js:278)
    at PortDuplexStream.Readable.push (_stream_readable.js:245)
    at PortDuplexStream._onMessage (index.js:38)

Also: Contact Copy Address button is vertically stretched, probably from the svg PR.