Updated copyright notices to include the year 2018.

quota: Prefix quota errors with backend name in quota_get_resource() Remove quota backend name error_r prefixing from get_resource() vfuncs.

quota: Return quota_get_result from quota_backend_vfuncs.get_resource() Add a QUOTA_UNKNOWN_RESOURCE_ERROR_STRING for returning error_r with QUOTA_GET_RESULT_UNKNOWN_RESOURCE. Forbid backends from returning QUOTA_GET_RESULT_UNLIMITED in quota_get_resource() with an i_panic().

quota-imapc: Improve error_r strings

quota: Add error_r to update() of quota_backend_vfuncs

quota: Add error_r to get_resource() of quota_backend_vfuncs

quota: Add error_r parameter to init_limits() of quota_backend_vfuncs

quota: Initialize quota_backends with designated initializers

quota: Fix failing again if quota setting has invalid parameters This was broken by the recent quota parameter parsing changes.

quota: Fix imapc backend not to try to find out mail's size. This removes unnecessary FETCH RFC822.SIZE command sent to server when expunging mails.

Whitespace cleanup

imapc backend parameter parsing changed to use common function

imapc-quota: Avoid sending unnecessarily many GETQUOTA[ROOT] commands The last_refresh == ioloop_timeval check didn't work, because the refresh itself updated ioloop_timeval. This caused a single quota lookup to issue multiple GETQUOTA[ROOT] commands to imapc.

quota: imapc backend now never enforces the quota itself It just causes a lot of GETQUOTA/GETQUOTAROOT calls to remove. In theory we could make this optional, but I doubt anyone would want it.

quota: Add imapc backend This allows using imapc storage with imapc quota. The quota acts as read-only, so it's used only when the current quota usage is explicitly asked. The quota can be looked up using either a mailbox name or quota root name. By default INBOX's quota is looked up. If there are multiple quota roots returned for the mailbox, only the first quota root returned by the QUOTAROOT reply is used.