Edited the first two chapters for increased legibility.

'Getting started' and 'Creating your own module' have been
merged.  'Getting started' should contain something simpler,
like building and compiling the grid howto.

Actually, the description on how to create your own module
explains for the most part how you copy'n'paste files from
dune-grid to fit your own module.  It makes you wonder why
duneproject doesn't do that for you.

I also ran the spellchecker.  A very helpful tool indeed!


[[Imported from SVN: r5462]]