FLOE-164: Separated the simple editor and the metadata panel.
FLOE-164: Code improvement and styling fix.
FLOE-164: Refactored code to better modularize metadata and simple editor. It includes: 1. moved the video grade component "fluid.metadata.videoMetadataPanel" for defining video metadata and the general wrapper component "fluid.metadata.metadata" for media grade components into metadata source code directory rather than having them in demos code, as well as completing unit tests for them; 2. kept the save metadata functionality in demos.
FLOE-164: Use the namespace demo.metadata for instantiating metadata demo.
FLOE-164: Add the line to initialize the "demo" variable.
FLOE-164: Changed the variable scope of the "demo" variable.
Merge remote-tracking branch 'cindy/FLOE-164'

* cindy/FLOE-164:
  FLOE-164: Changed the variable scope of the "demo" variable.
  FLOE-164: Add the line to initialize the "demo" variable.
  FLOE-164: Use the namespace demo.metadata for instantiating metadata demo.
  FLOE-164: Refactored code to better modularize metadata and simple editor. It includes: 1. moved the video grade component "fluid.metadata.videoMetadataPanel" for defining video metadata and the general wrapper component "fluid.metadata.metadata" for media grade components into metadata source code directory rather than having them in demos code, as well as completing unit tests for them; 2. kept the save metadata functionality in demos.
  FLOE-164: Code improvement and styling fix.
  FLOE-164: Separated the simple editor and the metadata panel.