Update outdated SyncMachine docs

`initSyncMachine` was removed in 72863848337f47ca3216ff6f443d8ba7bf571fcf.
Change `@` to `this`
Merge pull request #473 from iangreenleaf/sync_machine_docs

Update outdated SyncMachine docs
Typo fix
`reverse` helper for easy access to router lookups
Merge pull request #469 from iangreenleaf/url_helper

urlFor helper for easy access to router lookups
Chaplin.helpers.reverse: throw error if the route was not found.