Move enums and various utility methods to util module
Move view macro to tig.h
Move request definitions to request.h
Move request handling code to request.c
Move line definitions to line.h
Move line and color code to line.c
Move keybinding and run requests to keys.[ch]
Move view declarations to view.h
Add tool to generate doc from data structures
Move repository information to repo.[ch]
Move refs helpers to refs module
Group environment-based options
Use symbols to track diff and log argument formatting
Move option declarations to separate files
Move option handling code to options.c
Move view draw methods to draw module