Set background colors on login storyboard views

Match the colors used in the rest of the application.
URL encode email for password reset API

The API was returning errors unless this the email address is encoded.
Update pass reset messages and behavior

Previously, the app was not showing a success message with instructions
on what the user should do next.

I also added messages that differentiate between a service failure and
the user specifying an email address that is not connected with an
existing account.
Merge branch 'topic/password-reset'

Conflicts:
	OpenTreeMap/src/OTM/OTMAPI.m