Diamond operator isn't supported in older IDE's.

I don't see any real benefit in imposing the diamond operator -- Object<>() -- in the library. By not using it, the source code will NOT show as a syntax error in old IDE's (Google updated their IDE lately to support JDK 1.7, which is still behind the recent one anyway.)
Merge pull request #517 from orientalsensation/RemoveDiamonds

Diamond operator isn't supported in older IDE's.
Update AsyncHttpResponseHandler.java

fix onProgress method's log about progress always 0% because bytesWritten's type is int
and totalSize 's type is int ;int/int is 0
Merge pull request #521 from gaobq/master

Update AsyncHttpResponseHandler.java
Use indexes for array parameters
Store array/list size in a local variable for performance
Cast params to string by default
Enable changing handler's operation mode in run-time.

The handler had a bug when switching from async to sync, and vice-versa.

Because the handler variable was final, switching from async to sync would not free the retained memory. Also, and more importantly, if the handler was sync and then switched to async, a NPE would result because the handler was always null from before.

This is now fixed.
Add getThreadPool() method to return current thread pool used.
Small logical error.
Enable custom classes to override the default threading behavior.
fix an exception
Merge pull request #526 from ldiqual/master

Use indexes for array parameters
Merge pull request #528 from ldiqual/bugfix/default-cast-string

Cast params to string by default
Merge pull request #533 from superdry/fix

fix an exception
Merge pull request #531 from orientalsensation/AsyncHttpClient

Added ability to get thread pool or set the default one when extending.
Merge pull request #530 from orientalsensation/AsyncHttpResponseHandler

Enable changing handler's operation mode in run-time.
Fix a logical bug when setting async/sync mode.
Merge pull request #534 from orientalsensation/ResponseHandler

Fix a logical bug when setting async/sync mode.
Not starting many threads to cancel requests, just one #533