Compile library with -Wall.
Add amqp-builder to cabal file.
Fixed all warnings.
Removed redundant newlines and whitespace.
Reordered imports.
Consistent export layout.
Use LANGUAGE pragma instead of OPTIONS and -X.
Consistent use of type variables.
Eta-reduce function definitions.
Removed redundant return.
Removed redundant do-notations.
Use const.
Use maybe.
Use unless.
Use liftM2.
Minor layout tweaks to improve readability.
Improved comment layout for readability.
Replaced amqp 0.8 specification with ampq 0.9.1.
Generated new interface according to amqp 0.9.1 specification.

Note that the meaning of "major" and "minor" version shifted with 0.9.1: 0 is major, 9 is minor, 1 is revision.
Allow arbitrary arguments to be provided to consumeMsgs.