IDEX-1667: rename GenerateDescriptor -> GeneratorDescription
New editor mthod: refresh()
IDEX-1700 Refresh editor display when activated
Merge pull request #359 from mleduque/IDEX-1700

IDEX-1700 Refresh editor display when switching active part
Merge pull request #360 from codenvy/IDEX-1667

IDEX-1667: rename GenerateDescriptor -> GeneratorDescription