Remove useless/deprecated macros in code

As the code is littered with useless macros, I've decided to clean it up a bit.

These modifications have been applied only to live code (not commented-out or in the legacy module)

* Removed instances of CV_CALL
* Removed instance of OPENCV_CALL
* Revised macros so they don't call constant functions (cvGetErrStatus / cvSetErrStatus)
* Removed cvGetErrStatus / cvSetErrStatus from code

Also, I had then to remove the compilation warnings (unused values) and only then I've modified legacy code.

Because this is the 2.4 branch, no application-facing file has been modified directly (so the macros are still in the header-files and cvGetErrStatus is still in the final library).