As a chat user, I wish to have access to a setting page, so that I can configure my application to my preferences

[Enderknight2016]

Acceptance criteria:

• buttons for changing the application theme are present, even if they don't change the theme.
• A way to view the user's full device information is given.
• a way to access a separate fragment, the nickname list, is given.
• the settings exist in a fragment, not an activity
• add a setting for message history length to resolve issue #10 with a default of never forgetting a message (implementation can wait until #14 is finished)