lightly pulse values when they change in the environment pane
Merge remote-tracking branch 'origin/master' into feature/environment-improvements
improve environment pane handling of large objects, long vectors, and pathological cases
Merge pull request #47 from rstudio/feature/environment-improvements

Improve environment pane handling of large objects and long vectors
initial support for filter-by-name in environment pane
highlight portion of name or value that matched filter text
make filter case-insensitive
Merge pull request #48 from rstudio/feature/environment-improvements

Filter objects in the environment by name or value