Manage dynamic job chains

The built-in web interface is improved for the following operations:

• Add new job chains on the fly.
• Such job chains are created from existing jobs.
• Support for simple chaining of job node states: the state is automatically assigned, and could be adjusted by the user.
• No new jobs are created, the job chain addresses existing jobs and is added to the Job Scheduler by XML commands.
• Job Chains are removable by user operation in the built-in HTML interface.