More small header changes:

* Remove leading underscores in header preprocessor names
* Regularize names to include directory parts in the file name
* Untabify files
* Update copyright and remove unmaintained cvs $Id$ line

The justification for removing leading underscores comes from a CERTS Secure Coding recommendation: https://www.securecoding.cert.org/confluence/display/cplusplus/DCL32-CPP.+Do+not+declare+or+define+a+reserved+identifier

See also Savannah bug #35745 https://savannah.gnu.org/bugs/?35745

lib/driver/portable.h

@@ -21,8 +21,8 @@
    included other routines can be more portable.
 */
 
-#ifndef __CDIO_PORTABLE_H__
-#define __CDIO_PORTABLE_H__
+#ifndef CDIO_DRIVER_PORTABLE_H_
+#define CDIO_DRIVER_PORTABLE_H_
 
 #if defined(HAVE_CONFIG_H) && !defined(__CDIO_CONFIG_H__)
 # include "config.h"
@@ -51,4 +51,4 @@
 # define drand48()   (rand() / (double)RAND_MAX)
 #endif
 
-#endif /* __CDIO_PORTABLE_H__ */
+#endif /* CDIO_DRIVER_PORTABLE_H_ */