Merge branch '23-objects' into 25-from-2.15.1
Merge branch '23-applydefine' into 25-from-2.15.1
Merge branch '24-scalars-gc' into 25-from-2.15.1
take datasets package from 2.15.1 (only slight diff)
take grDevices package from 2.15.1, with slight pqR mod to src/chull.c
take compiler package from 2.15.1 (changes are slight)
Merge branch '25-from-2.15.1' into 26-debug
NEWS update
pmin/pmax change
saved example output for datasets/grDevices from 2.15.1
modify reg-tests-2 for pmin/pmax change, as in 2.15.1
mods updates
NEWS update
Merge branch '25-from-2.15.1' into 26-debug