Fix: ImageComparer.GetHashCode not comparing images correctly.
Change: Get all images for both characters and tabs at the same time at
login.

This reduces the amount image retrival requests by removing duplicates.
It also affects the amount of image loaded messages at login (removed
about 75% of the messages for me).
This should give a small load time reduction at login depending on the
amount of items.
Fixed error checking before the characters are loaded.
Fixed code formatting.
Merge pull request #1 from BlueManiac/master

Fixed bug in ImageComparer.GetHashCode()
Updated LoginViewModel to use a distinct list for loading images