Add LiveLeak implementation and tests

Note: LiveLeak only works with HTTP. No HTTPS.
Fix Youtube thumbnail size problem

Fix the aspect ration of Youtube thumbnail.
Also fix minor typo and format issue.
Add Dailymotion implementation and tests
Change Site/Common interface Translator

1. Modified Site/Common::translatable to output extra information
2. Modified Site/Common::translate to accept extra information
3. Modified all Site/Common implementations
4. Modified Translator::translate to pass the extra information