Compliant original Range's documentation style

  * range_utiltiy/as_container
  * range_utility/regular
  * range_utility/split_at

Signed-off-by: Kohei Takahashi <flast@flast.jp>
More compliant original Range's documentation style

  * access/at
  * access/back
  * access/front
  * access/optional_at
  * access/optional_back
  * access/optional_front
  * access/value_at
  * access/value_back
  * access/value_front

Signed-off-by: Kohei Takahashi <flast@flast.jp>
Merge branch 'OvenToBoost/master' into oven