Werk #6628: Improved timeperiod management

The timeperiod management pages have been improved ins several ways:

• Timeperiods can now be cloned.
• Configuring equal times for all weekdays is now easier. Instead of setting the same time ranges for each weekday it is now possible to select "Same times for all week days".
• Timeperiods listed in the excludes list are now sorted.
• The number of time ranges per day is now flexible. The dialog starts with a single time range. You may click on "add time range" to add more.
• Improved validations of input values.
• The builtin timeperiod 24X7 is now always visible. The implicit existance of this timeperiod confused users.

To the list of all Werks