Fix build under NetBSD 6.

* Avoid conflict of tolower function, Thank you, tsutsui@ (PR pkg/49262).
* GCC 4.6 is required to support nullptr at least.
Update to 0.10.12.1

changelog:
Changes in version 0.10.12.1

 * Fixed compilation on non-head GHCs

Changes in version 0.10.12.0

 * Export MVector constructor from Data.Vector.Primitive to match Vector's
   (which was already exported).

 * Fix building on GHC 7.9 by adding Applicative instances for Id and Box
Updated devel/hs-vector to 0.10.12.1
Bump PKGREVISION for hs-vector-0.10.12.1