client: move the throlling code outside of the grid

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
save the old center

Signed-off-by: Sébastien Boisvert <sebastien.boisvert.3@ulaval.ca>
Merge branch 'master' of git://github.com/sebhtml/Ray-Cloud-Browser