Log Message:
tex-beamer{,-doc}: update to 3.66

3.66
### Fixed
- fixed edge case in numbering of hidden and unnumbered frames
- fixed regression of class options not being passed to packages
  like xcolor

3.65
### Added
- adding new `onlytextwidth` class option to use this key for all
 `columns` environments by default
- adding new stretchable frame option `s`
- adding user-accessible commands for `\beamersidebarwidth` and
 `\beamerheadheight`
- allow custom values for `aspectratio` option

### Fixed
- using `gray` colormodel for the delcarartion of fadings
- fixed bullet colour of alerted items for custom item colour
- workaround to make miniframes clickable in xelatex
- added missing encoding value to multimedia sound macro
- imporoved problem with shadow of blocks without title
- reduced artefacts in poppler based viewers for shadow blocks
- workaround to make `\framezoom` clickable in xelatex
- exclude invisible frames from being counted
- fixed cut off miniframes for 8pt and 9pt