Make canned double exp integral rules.

[emsr]

Maybe max of 128. Lower power of 2 rules could skip in that single list. The weights will differ.

[emsr]

I made a build_double_exp_rule and ran it on all the types from 128. The abscissae saturate at 1 about half way through.
Consider double word abscissae and maybe weights.
Maybe if the b-a was huge double word would help.
Maybe the upper limit is just nuts.