SettingsSection: Add a setting to force the rotation lock

This merge request brings a force rotation lock setting:

• This setting enables the user to automatically enable the rotation lock option when the video player is displayed.
• The orientation that will be locked is the one selected by the device when the video player is displayed for the first time. It remains the same until the option is disabled or the video player is killed.

This merge request also brings some changes to SettingsSection.swift file:

• The coding style has been reviewed and a few chunks of code have been simplified.
• The .opticID switch case that was previously removed and was generating a warning which could lead to an error in Xcode 6.0 has been added back (regression introduced by: f303daab)

Closes #1869 (closed)