Extract function for determining a party colour to a utility class.
Extract function for finding a member's image to a utility class.
Move existing namespaced classes to subfolder.

This allows for the autoloading of classes in the root namespace, ie the
rest of TheyWorkForYou.
Move MEMBER class to use autoloading
Move postcode functions to autoloadable utility class
Move Gaze to the Utility namespace (for consistency)
Move constituency functions to autoloadable utility class
Fix case of Utility folder

Travis is particularly caring of the case of folders, even though PHP
doesn't care (and will be happy with all commits to this point anyway)