Rename "Scan for new extensions" to "Scan for installed extensions".
Review Request #6072 — Created July 7, 2014 and submitted
This renames the scan action to say "installed" instead of "new," making
it more clear that we're not looking for new extensions from some remote
source, but rather those that have since been installed.
Saw the new wording.
Tool: Pyflakes Ignored Files: djblets/extensions/templates/extensions/extension_list.html Tool: PEP8 Style Checker Ignored Files: djblets/extensions/templates/extensions/extension_list.html