Implement lock in Param for extern. Add example with media ImageGenerator.
Do we need to block it if changed by extern?
Merge pull request #125 from kritchie/perspective

Perspective
Fix when param missing lock var (lock is None)
config: Propose timestamp with 24 hours for log file.
Add feature keep_alive_media
This will not close media if opened. Useful if take a long time to open it.
add fourth column (prvw) in rec hist

The purpose of that column is to watch the rec file in preview.
Double-click on the cell (eye icon) to execution action.
Param: notify send itself, and add lock and unlock.
bug fixed. Preview is created on a new execution.
Fix lock param from server update.
Move publisher in resource.
Move publish media and filter info into his class.
Remove log from update param.
Merge pull request #126 from seblago/dev

add fourth column (prvw) in rec hist
Fix when missing private_config.
fix pep8
Fix param button. Add example with imageGenerator.