Added support for client-ID to prevent reacting to changes triggered by oneself.

However, it shows that we have some sort of cascade going on, as
a change triggered by someone else will cause our state to change,
triggering yet another state change.

This gets worse the more clients there are.
Now update-cascades will not be triggered by javascript anymore.
Now the file-exclude-patterns GUI seems to work correctly.
Implemented write-timeout to allow long-running godi instances.

After 5 minutes, the write-lock will be removed to allow others to
use the web interface as well.
Improved feedback loop handling

Even though the feedback loop issue still occours when network
delays are bigger.

This is a major issue that needs resolution
Added a workaround, reducing the update rate on file exclude patterns considerably.

Even though this fixes the loop issue, it doesn't properly handle changes
of existing user indices. These will end-up duplicated and remove
one of the preset filters.