Updated the various plugins to use OAuth 2.0 for authentication
against google apis. Google are phasing out AuthSub and pushing OAuth as
the replacement.
This changes repository_googledocs, repository_picasa,
portfolio_googledocs and portfolio_picasa
The token for requests is now stored in session rather than a user
prefence and it persists less but doesn't bother the user more than
necessary.
The google docs portfolio plugin is converted to use resumable upload
API as this appears to be what Google have replaced this with.
Unfortunately unlike authsub OAuth will require some setup by admins,
this is linked as a docs page.
From now on, all English strings use the new syntax. They are not
eval()'ed any more and the only valid placeholders are {$a} and
{$a->foobar}. No extra quotes escaping, dollar sign escaping and putting
double percent signs.
The modified files were exported from AMOS database repository in the
new syntax and were re-ordered by stringid. Standard GNU/GPL and PHPdoc
blocks are added. Where there was no copyright note so far, I added the
default one with Martin Dougiamas as the copyright holder.
Live long and prosper.