0.6.0 - Major API overhaul

The connection pool acquisition is now explicit and is no longer handled by the Session monad. This should provide for a simpler integration with other libraries.
The Session monad is now merely a convenience thing for providing a context to multiple transactions. One can run it as many times as he wants - it won't reestablish any resources any more.
The connection timeout is now set using Int for simplicity.
There are no exceptions any more. All the error-reporting is typed and done explicitly, using Either.
The error types are now mostly backend-specific.
The transaction mode is now extended to support uncommittable transactions with the TxWriteMode type.
All Tx functions are now appended with a "Tx" suffix.
Added vectorTx and maybeTx and updated the semantics of singleTx.
q statement quasi-quoter is now renamed to more meaningful stmt.
The Statement type is renamed to Stmt and is now exported from the main API.
RowParser is now uninstantiable. This enforces the idiomatic usage of the library.
Statement templates now support UTF-8.

0.5.0