Only do trick when enabled, check neg as well as pos NA/NaN
Merge branch '03-ISNAN' into 04
Merge branch '03-ISNAN' into 04-vec-enlarge
move type sets to Rinternals.h, update mods entry
Merge branch '03-inlined' into 04
Merge branch '03-inlined' into 04-vec-enlarge
make function ptr use conform to C99
Merge branch '02-evalv-prim' into 03
Merge branch '02-evalv-prim' into 03-ISNAN
Merge branch '02-evalv-prim' into 03-contexts
Merge branch '02-evalv-prim' into 03-def-COPY
Merge branch '02-evalv-prim' into 03-fast-base
Merge branch '02-evalv-prim' into 03-fast-const-eval
Merge branch '02-evalv-prim' into 03-fast-spec
Merge branch '02-evalv-prim' into 03-protect
Merge branch '02-evalv-prim' into 03-matchArgs
Merge branch '02-evalv-prim' into 03-getAttrib
Merge branch '02-evalv-prim' into 03-inlined
Merge branch '02-evalv-prim' into 03-install
Merge branch '02-evalv-prim' into 03-parens