Reverting changes to libs/afio/drd.supp

Changes to this file in a previous commit wre unhelpful. This commit undoes those changes.
Added Test Suites to unit tests, and fixed travis.yml to properly exclude async_io_errors using Boost.Test

Added 2 Test Suites:
1. all,  which contains all the unit tests
2. exclude_async_io_errors, which only excludes async_io_errors, as Boost>Test does not have a nice exclude command like CATCH

compiles under GCC 4.7