Skip showing the info menu if the RMB is bound.
Use [Unknown]'s suggested method instead.
Correct return values, validation in sdkver funcs.

I am unable to reproduce any validation, so these changes make it match
tests on a PSP.  But then, maybe it's my custom firmware getting in the
way?  Added reporting to see the effect better.
Spelling fix.
Match test in sceUmdUnRegisterUMDCallBack().

Seems that 0 is the unregistered value based on how it reacts to that
param, and it should return 0 for success in newer sdk versions.
Merge pull request #5285 from unknownbrackets/umd-minor

Match test in sceUmdUnRegisterUMDCallBack()
Merge pull request #5283 from unknownbrackets/sdkver

Correct return values, validation in sdkver funcs
Merge pull request #5282 from thedax/rightMouseButtonFix

If the RMB is bound to a cancel key, don't show the info menu.