Add unit tests for GPIO bug fixes

Merge in changes from QEMU v2.1.1 (that happened since v2.1.0).

Merge from master v2.1.1 tag.

Update STM32 files for compatibility with QEMU v1.5.1

Update VERSION for 1.5.1 release

Signed-off-by: Anthony Liguori <[email protected]>

update VERSION for 1.4.2

Signed-off-by: Michael Roth <[email protected]>

Update version for 1.5.0 release.

Signed-off-by: Anthony Liguori <[email protected]>

Update version for 1.5.0-rc3 release

Signed-off-by: Anthony Liguori <[email protected]>

Update version for 1.5.0-rc2 release

Signed-off-by: Anthony Liguori <[email protected]>

Update version for 1.5.0-rc1

Signed-off-by: Anthony Liguori <[email protected]>

Update version for qemu-1.5.0-rc0

Signed-off-by: Anthony Liguori <[email protected]>