itaps-parallel DOCUMENTS subdirectories

[Lori A. Diachin]

When we create the new subdirectory that has all the tutorial examples, 
I think we should have a single subdirectory that contains the iMesh.h 
iMeshP.h and iBase.h files that all the exercises can reference.   
Essentially Karen's DOCUMENTS directory from Hello.  Martin also refers 
to these functions and it doesn't make sense to repeat the 
subdirectory.  I'd probably change the name to be more iMesh specific - 
something like iMESH_INCLUDES or iMESH_DOCS.

We'll also need a high level README that describes each of the exercises 
at the highest level.

Just wanted to get these ideas out into public space - no immediate 
action items.

Lori