Merge pull request #10 from feixie/master

moved get company detail api call
Renamed SeekerOrRecruiterViewController to SettingsViewController.
Display TabBarController if user already logged in.
Created stub view controllers for main view and messages view.
Switch tab content view controllers based on Candidate/Hiring Manager segmented control.
Create tab bar item for each tab.
Updated tab bar item icons.
LogInViewController styling.
Merge pull request #11 from ahuang13/tabs

Logic for tab bar controller
Merge pull request #12 from ahuang13/login_styling

LogInViewController styling.
adding back init tab bar