Merge pull request #289 from pborreli/typos

Fixed typos
readme: tell people to use alpha-r2748 instead of release-1.5.27.1-beta
system: roll back fd optimization
beacon-handler: don't screw up the connection
Merge pull request #299 from pagespeed/jefftk-rollback-fd-opt

system: roll back fd optimization
Merge pull request #276 from pagespeed/jefftk-post

beacon-handler: don't screw up the connection
merge commit