Fixed errors and warnings reported by makeinfo
Remove `LAST-UPDATED' from `bongo.texinfo'
Use `load-file-name' instead of `find-library-name'
Add bongo-pkg.el (for `M-x package-install' support)
Simplify headers, remove unneccesary files
Drop support for Emacs 21
Delete obsolete functions and variables
Move `etc/' to `images/'
Move `bongo.texinfo' to `bongo.texi'
Move `contrib/tree-from-tags.rb' into root directory
Move `README.rdoc' to `README' and remove markup
Add simple `afplay' backend (for OS X)
Update NEWS
Add autoloads to the most common entrypoints