Allow HTTP authentication without password.

This makes it the plugin useful for any form of webserver-based
authentication (CAS, SAML, etc.); of course, other plugins will
have to be installed to handle connections to the IMAP/SMTP
servers, but at least they don't need to duplicate the basic
HTTP authentication functionality.
Substitute variables in 'password_ldap_search_base' value
Add filetype icons for Powerpoint and Openoffice Presentations (#1489225)
Merge pull request #141 from rasky/http_without_pwd

Allow HTTP authentication without password.
Finish advanced prefs feature (#1488829)
Merge branch 'master' of github.com:roundcube/roundcubemail
Adjust date column size to fit the widest possible date format (#1489368)
Update Changelog
Adjust recipients textarea size according to conent.
This reduces the height to 1 row on Firefox < 25 which renders textareas rows+1 heigh (#1489198)
Better icon for advanced settings blocks; message list row borders
Fix listicons image with wrong message header icon