This now follows the approach used for bearing formats, where a user
can defined a default coordinate format for newly created projects
in the Settings - Options - Map Tools section.
New projects will inherit that setting, but the format can then
be changed through the Project Properties - Coordinate Format button.
This ultimately exposes more control to users for how coordinates
are formatted for a project, eg allowing them to control whether
direction suffixes are shown, and whether leading or trailing zeros
should be included.
Move vector, project and network related core .cpp/.h files into
dedicated subdirectories.
An attempt to organise src/core better to make things easier to find.
