Add Gruntfile.js with install and uninstall tasks
add task for updating composer.json for deployment branch
Update README
Remove task alias
Add 'dev-' to branch name in composer.json
Make branch task do clean + update composer + install
Fix autoload suffix to ensure it is valid
Use autoloader suffix (if set) in cache key

We can then use this setting in combination
with the one in wmf config (based on sites/branches).

This gives us a way to invalidate the cache key
in sync with code changes.  When we want to do so,
such as for a backport, then we change the autoloader
suffix.  If we don't need to invalidate cache,
then don't update it.
Add details to readme about deployment config generated

autoloader-suffix is set in composer and sharedCacheKeyPrefix setting is also set.
Merge pull request #9 from wmde/grunt

Add Gruntfile.js with install and uninstall tasks