Improved description of com.openexchange.servlet.maxInactiveInterval property:

# The initial maximum time interval, in seconds, between client requests before a HTTP session is invalidated.
# This only applies to the HTTP session controlled by special JSESSIONID cookie, and does therefore not influence life-time of Groupware session.
# A negative value will result in sessions never timing out.
# If the attribute is not provided, a default of 1800 seconds is used.
com.openexchange.servlet.maxInactiveInterval=1800