Update README.md

Update Version 4.5 description
Enhance video control by the master: remove control for slaves + fix bugs
Update README.md

Update Version 4.5 description
Issue #3: Enhance video control by the master: remove control for slaves + fix bugs
Issue #2: Formidable module installation
Issue #3 and #4: Enhance video control (pause videos when slide change) and fix bugs on presentation upload
Issue #2: Update Formidable
Issue #12: User connection during a video (users connecting while videos playing will be synchronized automatically to the videos currunt time)
Issue #4: fix bug for Firefox and IE
Issue #13: Access to all presentations
[Cleanup] spaces and indents
Issue #13: Access all presentations