Merge pull request #6 from ypzhao/cloud-new

dynamically loading tizen apis
Merge pull request #11 from ypzhao/cloud-new

change the dropbox repository from git@github.com to git read only
Initial implement github extension for brackets
Fix github extension couldn't load github project properly

Fix the problem that github extension couldn't load the project which
the user name is same as repo name.
Fix the problem that github extension open large project 'SecurityError'
rename node-brackets_shell.js to brackets_shell.js
Extract fs API from brackets_shell.js as independent module to fsDrives