Notify user on transaction received

[ngotchac]

Closes #2556 until we have a pub/sub mechanism.

Browser notifications will be created whenever we detect an increase in an account value (in ETH or any other registered token). On click, the user is taken to the account page.
This might not work if the account receive n eth while sending n eth in the same block.
A pub/sub mechanism would be better, but isn't available atm.

[coveralls]

Coverage decreased (-0.5%) to 85.592% when pulling 129056a on ng-transaction-notify into 341777d on master.

[jacogr]

Merge in master for gitlab builds.

[jacogr]

Not 100% convinced of this UX -

Seems to work however. Closes way too quickly to even try to interact with it and click.

[ngotchac]

This is the default Chrome behavior with notifications. We cannot get away without it.

The timeout is set to 5sec. Could increase it. 10 ? 20 ?

[coveralls]

Coverage increased (+0.003%) to 85.604% when pulling f65695c on ng-transaction-notify into 08a47ea on master.

[coveralls]

Coverage remained the same at 85.601% when pulling f65695c on ng-transaction-notify into 08a47ea on master.

[jacogr]

20s is probably a bit long, but ok as a start, easy enough to adjust downwards.