Address Issue 67: Updates for latest release

Note: This PR currently contains the changes for PR #68 as well.

Adds section on "time-split" vs "process-split" schemes
Adds some tips for allocating memory in a way that allows "stateless" schemes (though we don't use that term)
Make some format and wording consistency changes
Some format and wording fixes
Clarify some rules as actual rules and not just suggestions

NCAR / ccpp-doc