setuid and setgid accept string as a parameter.

Both process.setuid and process.setgid can accept either a numerical ID or a username\groupname string.
Added overloaded version of setgid and setuid.

Instead of making argument's type 'any' we have overloaded version for number and string parameters.
Added definitions for GAE's Channel API library
Merge pull request #469 from AntonAM/patch-1

setuid and setgid accept string as a parameter.
Merge pull request #474 from vvakame/add-gae-channelapi

Added definitions for GAE's Channel API library
Updated signature.
Merge pull request #476 from kazimanzurrashid/master

Updated the js-fixtures