Add %newobject to track newly created objects better
Add %newobject to track newly created objects better

Pool provides alternative constructors for a number of objects related
to 'pool' as 'create_xxx'. Add %newobject modifiers to those methods
in order to have those object properly tracked and destructed.

+ some documentation improvments.

ryppl/sat-solver,ryppl/sat-solver,ryppl/sat-solver,ryppl/sat-solver,ryppl/sat-solver