(PDB-686) Add warning about PDB-686 to release notes
(PDB-686) Add warning about PDB-686 to release notes

This adds a warning about PDB-686 to the release notes so users know how to
work-around it.

This also cleans up the linking in our current release notes, and removes the
warning about Puppet 3.4.x, because we pin against 3.5.1 and greater anyway.

Signed-off-by: Ken Barber <470bc578162732ac7f9d387d34c4af4ca6e1b6f7@bob.sh>

johnduarte/puppetdb,puppetlabs/puppetdb,waynr/puppetdb,rbrw/puppetdb,senior/puppetdb,kbarber/puppetdb,rbrw/puppetdb,waynr/puppetdb,mullr/puppetdb,grimradical/puppetdb,waynr/puppetdb,rbrw/puppetdb,mullr/puppetdb,puppetlabs/puppetdb,shrug/puppetdb,rbrw/puppetdb,wkalt/puppetdb,wkalt/puppetdb,rbrw/puppetdb,mullr/puppetdb,shrug/puppetdb,ajroetker/puppetdb,ajroetker/puppetdb,kbarber/puppetdb,highb/puppetdb,johnduarte/puppetdb,puppetlabs/puppetdb,grimradical/puppetdb,kbrezina/puppetdb,mullr/puppetdb,mullr/puppetdb,kbarber/puppetdb,ajroetker/puppetdb,senior/puppetdb,puppetlabs/puppetdb,senior/puppetdb,shrug/puppetdb,highb/puppetdb,kbrezina/puppetdb,kbarber/puppetdb,kbrezina/puppetdb,grimradical/puppetdb,wkalt/puppetdb,kbrezina/puppetdb,ajroetker/puppetdb,shrug/puppetdb,highb/puppetdb,wkalt/puppetdb,grimradical/puppetdb,senior/puppetdb,waynr/puppetdb,puppetlabs/puppetdb,highb/puppetdb,johnduarte/puppetdb,johnduarte/puppetdb