Add error messages when wrong pin is entered

[Tbaut]

• fix [UX] Account creation, give feedback for PIN typing and confirmation #156
• added error messages at pin creation when pin is too short or don't match
• added an error message at account unlock

Screenshots:

[lexfrl]

cool! Could you attach some screenshots also?

[lexfrl]

LGTM! Small grumbles though

[Tbaut]

Did some cleanup for unused components or functions (sometime I just commented it, will remove it if it's ok, along with the console.log)

^ the description of the issue :) I'll remove those console.log of course, it's a WIP requesting feedback in general.

[Tbaut]

It should be good to go if you want to have a look :)

[lexfrl]

As we discussed before, we's better to not change the current onChange behavior. What we decided to do is to just show user the current "unlocking" status.

[Tbaut]

Here we go, I've moved the error message to the state.
As we discussed, I don't think it's possible to leave the onChange function unchanged as I need to pass the information if the pin is wrong or right. If should now work well on iphone as well.

Let me know your thoughts.

[lexfrl]

perfect! One small grumble.

[lexfrl]

could be leaved as just this.setState({ pin });