Asynchronous and Child Transactions

The major new addition for this release is support for asynchronous transactions and child transactions. This significantly expands the ability to define more complex transactions with arbitrary code, while still taking advantage of asynchronous, batched transaction handling with off-thread start and commit operations. In addition, there is also support for child transactions (which are also asynchronous by default), which allows for asynchronous transaction operations to have full abort/roll-back functionality. See the documentation for the new transactionAsync and childTransaction methods.

As part of these changes the transaction method is now deprecated (which runs a synchronous transaction), as it will be converted to running asynchronous transactions in the future. Also the batch thresholds have been removed as there are too many complications with trying to run an asynchronous batch synchronously.