eliminating a cause of my recent rant and argument with Matt

[Barry Smith]

    I think a root of the miscommunication between Matt and I with  
regard to --with-mpi-shared is that --with is used for TWO different  
reasons

1) --with-mpi=0 --with-x=1 etc are used to indicate we want to turn  
off/on a package. In other words they are COMMANDS to BuildSystem

2) --with-mpi-shared=1, --with-sizeofint=8 tells BuildSystems FACTS  
that it would normally be figured out by BuildSystem. Usually they are  
provided on the command line because ./configure cannot run compiled  
programs (using --with-batch for example).

    I suggest we can the syntax for 2) and consistently use --known- 
mpi-shared --known-sizeofint=8 etc everywhere in help and BuildSystem.  
It makes things much clearer and can prevent loads of confusion.

    This is likely not compatible with how autoconf does things. Do  
they have a similar split and different names? Is there anything we  
can copy from their approach? Do we care?


    What do others think?

    Barry