Improve performance and other modifications

1. Fix a bug in CLI wrapper.js
2. camdemy, single file: use oEmbed for better performance
3. camdemy, folder: use /toc/ instead of /folder/
4. camdemy, folder: change the css select rule for image-based folder
   page
5. xuite: use request module instead of native http.request
Add PowerCam for Lee LinShan's videos and option 'all'
Fix bugs and some providers

1. Fix some error handling
2. Xuite change the location of media id.
3. Youtube introduced 'encrypted' signature.
4. Add NTU space