edit
It has 3 major enhancement and bugfix for AbstractAjaxCallback.java:

in function clear(), reset all local variables in order to reuse same
AbstractAjaxCallback instance.

in function httpDo(), add code for IOException processing to remove
partial content file in cache.

in function filePut(), add code for remove cache file when user called
status.invalidate() in case of status.getFile() is not null

4. checkable replace CompoundButton
use gradle
update
update commint Jun 20, 2013
update gradle version