Purge PHPStorm 9.x Settings on OSX Yosemite
# PHPStorm v9.0
rm -rf ~/Library/Application\ Support/WebIde90
rm -rf ~/Library/Cache/WebIde90
rm -rf ~/Library/Preferences/WebIde90
# PHPStorm v10.0
rm -rf ~/Library/Application\ Support/WebIde100
rm -rf ~/Library/Cache/WebIde100
rm -rf ~/Library/Preferences/WebIde100
# 1-liner for Version 10 (EAP)
sudo rm -rf ~/Library/Application\ Support/WebIde100 && sudo rm -rf ~/Library/Cache/WebIde100 && sudo rm -rf ~/Library/Preferences/WebIde100
# Or the Sudo 1-Liner command for Version 9.0
sudo rm -rf ~/Library/Application\ Support/WebIde90 && sudo rm -rf ~/Library/Cache/WebIde90 && sudo rm -rf ~/Library/Preferences/WebIde90