This patch allows to login as a proxy user on behalf of every other user when authentication-ldap and the MAL imap plugin is in use.
This allows e.g. to use the outlook uploader on behalf of the user without knowing the password of the user.

new parameters:

/opt/open-xchange/etc/groupware/ldapauth.properties:

# Comma separated list of login names allowed to login as a proxy for every
# other user.
#proxyUser=

# Define a delimiter to be used to seperate Proxy from Userlogin
# If defined, a proxy user can login on behalf of a user using the form
# <PROXYACCOUNT><DELIMITER><USERACCOUNT>
# NOTE: the underlying Mailserver must support SASL AUTHPROXYING
# The open-xchange mailfilterbundle does not support it, so it will
# raise errors
#proxyDelimiter=


/opt/open-xchange/etc/groupware/mail.properties:
# Define a delimiter to be used to seperate Proxy from Userlogin
# If defined, a proxy user can login on behalf of a user using the form
# <PROXYACCOUNT><DELIMITER><USERACCOUNT>
# NOTE: the underlying Mailserver must support SASL AUTHPROXYING
# The open-xchange mailfilterbundle does not support it, so it will
# raise errors
#com.openexchange.mail.authProxyDelimiter=