New patch release 4.6.2

Added details of Pronk, et al 2013 paper to README

Bumped version to 4.6.3-dev. The v4.6.2 tag points to the actual
version that built the tarball, which was patch set 1.

Change-Id: I9b17cd80f34e2d175dbed0d87677a0611254b7c7