acl plugin: Fix Coverity warning Just switch the MALLOC_ADD() parameters, so that arithmetic doesn't get inside a sizeof().

global: Make sure *_malloc() calculations won't cause integer overflows.

ACL: Crashfix to previous change. Also fixes "-id" to work correctly with missing "id". --HG-- branch : HEAD

Global ACLs now override all local ACLs. Also did some some internal in anticipation of ACL file update code. --HG-- branch : HEAD

SIZEOF_ACL_MASK() macro wasn't used as it was intended. Changed so it allocates enough memory for the struct. --HG-- branch : HEAD

Changed .h ifdef/defines to use <NAME>_H format. --HG-- branch : HEAD

Create dovecot-acl-list file that lists all mailboxes where non-owner has lookup right. Use the file when listing mailboxes in shared/public namespace. --HG-- branch : HEAD

Don't check ACL file's timestamp changes more often than once in a second. --HG-- branch : HEAD

Don't keep acl_objects permanently in memory. Moved cache validity information into cache records. Some other cleanups and fixes. --HG-- branch : HEAD

Added initial support for ACLs. Currently supports reading the ACLs from files. Since no proper support for shared folders exist yet, this is mostly intended to be used only for preventing users from fully accessing the mailboxes they'd otherwise have full access to. It anyway does support "master user" having different ACLs to mailboxes. --HG-- branch : HEAD