Line pages

-Introduce first line pages, including CSS for maps
-‘Easy’ maps only for now, so Bakerloo, Ham&C, Jubilee, Victoria and
Wat&C.
-Line pages pre-empt modularisation of sidebar.
Modularise sidebar

Adverts, Login, Status and Twitter migrated to separate PHP files;
still needs to be applied across the board.
Add Circle line page

This one was fun!
-Line diagram map for Circle line
-Associated CSS
-Future-proofing with border colours for all lines