Add wrapping and unwrapping capability to CKM_AES_GCM mechanism

[keldonin]

This PR adds wrapping and unwrapping capability to the CKM_AES_GCM mechanism.
It comes along with new cases to the test suite.

[keldonin]

The build seems to fail with Appveyor. However, when looking closer to the logs:

• all builds are on MSVC/Windows (no build on linux/BSD?)
• the builds fail as syslog.h cannot be found (and is probably not expected on this platform).

Is something broken in the source code, that prevents building on Windows?

"C:\projects\softhsmv2\softhsm2.sln" (Build target) (1) ->
"C:\projects\softhsmv2\ALL_BUILD.vcxproj.metaproj" (default target) (2) ->
"C:\projects\softhsmv2\src\lib\softhsm2.vcxproj.metaproj" (default target) (4) ->
"C:\projects\softhsmv2\src\lib\common\softhsm_common.vcxproj.metaproj" (default target) (5) ->
"C:\projects\softhsmv2\src\lib\common\softhsm_common.vcxproj" (default target) (6) ->
(ClCompile target) -> 
  c:\projects\softhsmv2\src\lib\common\log.h(40): fatal error C1083: Cannot open include file: 'syslog.h': No such file or directory [C:\projects\softhsmv2\src\lib\common\softhsm_common.vcxproj]

[saper]

@keldonin I found another issue with AES GCM and have a fix in #664. Since the fix would have need to be applied also to the wrapping code, maybe we should think about extracting those AES parameter checks into a common function. I have also refactored the test d155341 to be able to test different sets of parameters.

[rijswijk]

I think this requires the same fix as in #664

[rijswijk]

I think this requires the same fix as in #664

[jschlyter]

Please rebase on develop and mark as ready when ready.