More const-ness in code
Remove obsolete comment
Refactoring to use a sub-function
Adding notes about wrong way of attaching clauses in Simplifier
Ooops, forgot to check for FALSE. Instead, checked for TRUE :S
Check DRUP enable inside the function. It's cleaner
Bundle together var-elimination functions
Clean implicit clauses just before var-elim, not much before it
Allow Simplifier::propagate() to be called when solver->okay() is FALSE
Check if bounded variable elimination is turned on inside the function

It's cleaner this way
Removing double empty line
Propagate before and after re-adding long clauses in Simplifier

Before so that it's faster, and after so that Solver is in a correct,
propagated state
The comment wrong: it only cleaned blocked clauses marked for delete

And so it was useless. It was only useful in the old days when
elimination was weirdly behaving and setting values of just-eliminated
vars