ARIA common files now automatically copied to repos

I finally got around to setting up automatic synchronization from the 
aria-common repository to the other repositories. From now, whenever a 
change is pushed into the master branch of aria-common, the changes will 
show up in the common subfolder of the following repos:

  * accname
  * aria
  * aria-practices
  * core-aam
  * dpub-aam
  * dpub-aria
  * graphics-aam
  * graphics-aria
  * svg-aam

If there is a repo that should have been enabled for this 
synchronization but wasn't, let me know.

Some people, to work around the lack of synchronization, may have made 
changes in your the copies of the common files, i.e., in 
<repository>/common. If you have done so, those changes are now gone - 
but still available from the commit history. Let me know if something 
you needed has been affected, or make a pull request on the aria-common 
repo to restore it.

The acknowledgements file, in particular, is not working well as a 
"common" file. We also have less need for the localbiblio.js file. You 
are not forced to use these files, they are there for convenience. I'll 
work with the editors to make best use of these and expect to push some 
changes to how we structure the acknowledgements file, and in general 
try to make the common files a useful resource and not a burden.

Michael