Initial code review: acknowledge that Canceling is async and may fail (e.g.
if download had actually completed already) - adds two new states to the
progress UI.
Smaller cleanups: fix done() handler indents in Package.js; add "request"
to package.json; convert British "cancelled"->"canceled"; rename
"RealInstaller"; plus some other minor cleanups.
Code review: download files to OS temp folder (with dummy unique filename),
and pass a hint about the extension name to install() instead of having it
be directly based on the downloaded filename.
Also:
- Clean up handling of validation errors so the strings are rendered in
the UI properly.
- Tweak NodeConnection's error handling so exceptions thrown by client
code (such as Package.js or its clients) aren't misrepresented as
"received malformed message".
Code review:
- add missing const and corresponding error string
- remove defunct const and its error string; remove stray log()
- fix typo in assert
- remove unneeded var that duplicates closure
- fix how Node-side return vals are documented to match Inspector.json better
Merge pull request #3178 from adobe/pflynn/install-ext-codereview

Code review fixes for extension download