JS groups support

userGroups target for api urls
apiRequestString wrapper
group parsing with json content
Zotero.Groups: addGroupsFromFeed and fetchUserGroups functions
php - remove comments, add trash functions
python update

Brings python mostly in line with php updates.
Most significantly: switch to api v2, multi-object writes, most write functions
return the objects they modified/created rather than http response objects.
This means some of the python examples probably need to be updated.
add google reader starred python example
PHP update

Fix collection writing for v2 api and bring collection modification functions
in line with the changes to item modification functions.
PHP google reader starred items example