[petsc-dev] do not use \trl{ } on PETSc function names etc in the manual

[Barry Smith]

    Please do not use \trl{ } around PETSc function names etc that  
have manual pages UNLESS they have underscores in them. For example DO  
NOT do \trl{MatSolve()}. I just spent an hour removing a ton of  
unneeded ones.

    Thanks

     Barry

   The building of the manual automatically adds links for these  
things but cannot do that inside a \trl{}.

    Eventually I'll make it also automatically handle the underscores,  
but that comes later.