Merge pull request #66 from ksk-uchi/GG-2584-document-update

GG-2584 add two parameter to payload explanation.
Merge pull request #67 from ksk-uchi/GG-2584-document-update

GG-2584 add explanation about callback fired timing
Changed layout to match Gengo.com site

I changed the layout and a bunch of nav items to work with Gengo new
style.
Merge pull request #68 from gengo/test_new_layout

Andrea is watching over me.
Updated JS & Rakefile
GG-2584 modify dead links without default layout.
GG-2584 modify dead link on default layout