Fix typo in comment
Add config variable 'proxy_whitelist'

HTTP headers X_FORWARDED_* and X_REAL_IP are only evaluated when
received from an IP listed in proxy_whitelist. Furthermore, only the
last non-trusted IP from X-Forwarded-For is used in place of the real
ip.

Without this, an attacker can easily spoof the headers and control the
result of the ip or ssl check.

This fixes several problems with [3a4c9f42], [4d480b36] and [a520f331] as
mentioned in #1489729.
Remove usage of $RCMAIL global variable
Fix bug where "With attachment" option in search filter wasn't selected after return from mail view (#1489774)
Fix message UID extraction for _uid=*; update unread count for all affected mailboxes
Don't display error when moving a message to the same folder it already resides
Fix _uid=* case for regular selections
Optimize header fetching of multi-folder searches with natural (UID) sorting
Fix splitting message identifiers into UID and folder values
Add test case for #1489777
Don't remove messages from list when moving to another folder in multi-folder search mode, just update the list
Merge branch 'master' of github.com:roundcube/roundcubemail
Consider sort order in UID sort mode of multi-folder search results
Fix forwarding all ('*') messages of a search set
Enable listmode switch if listing is not multi-folder
Update Changelog
Make multi-folder message identifiers work with folders containing commas
Disable time limit for folder download requests
Hide PHP Warning: substr_compare() The length cannot exceed initial string length
Fix accidental key replacements