Submodule documentation

[Peter Hill]

Currently, when we update the submodules, people may need to manually sync them. We need to provide adequate documentation on how to do this, and how to recognise when to do it

[Bill Dorland]

Submodules == utils, Makefiles, etc? Is a directory like geo a submodule, too?

Sorry to be ignorant. The contours of the code suite shifted in a lot of ways over the last two years and I am still catching up.

[Peter Hill]

Yep, utils and Makefiles are submodules, and everything else is a normal directory.

No worries! I'm still in the process of familiarising myself with the project!

[David Dickinson]

This reflects the shared nature of utils and Makefiles, which were svn externals in the svn repository. Sub-modules are about the closest thing to this that git has.

[Peter Hill]

This is covered in PR #19

[Joseph Parker]

Resolved by PR #19