flash fullscreen hotfix (#217)

In ef01d81846f629d2e650eb79eeb7453b49cd5c14 a change to one line was
fatally omitted, now causing an error every time fullscreen is toggled
in flash mode.
Merge pull request #218 from blacktrash/flash-fs-hotfix

flash fullscreen hotfix (#217)
Controlbar stays fixed upon mouseout with fixed-controls CSS class, fixes: #219
Buffer and progress hotfixes for 5.3.1, #224