error in handling download external packages

[Barry Smith]

    After we have compiled the external package libraries we copy them  
over to the install site, ok.
But we also blindly copy over ALL of its include files over to the  
install site so that the PETSc interface
for that package can be built. But then we leave all those includes  
there even though they are not
needed by the user of the installed PETSc.

   Possible correction: put those includes in another directory that  
is used for building PETSc but not used
when compiling user code. Somehow need to pass the appropriate -I only  
when building PETSc
and not for user code.

   Barry

Even when we do not install the package, that is we use one someone  
already installed, we point
to its include files in our makefile system and continue to point to  
them (with -I stuff) when users
build code.