Rebase from 'upstream'
Added install rule for package.xml
add misc patches from Groovy
do not build the docs by default
import patch from itseez/opencv#1244
Turn off performance tests, tests, and docs for from source people
importing upstream diff http://code.opencv.org/projects/opencv/repository/revisions/e9b9a6fc038fc243e2debcc1dabd0d0745ff39d6/diff/modules/legacy/src/dpstereo.cpp