Updated changelog.md
More updates to changelog.md
Better description of Stagehand
Removed a yet-unavailable feature
Further release notes clarifications
Release notes
Merge pull request #3656 from ussuri/remove-useless-external-files

Removed useless files from external packages like demo.html, README.md etc.
Release note
add LG optimus v3 to usb device list
Merge pull request #3659 from sunglim/lgphone

add LG optimus v3 to usb device list
Remove more useless files