* common/util.h: Provide replacement for GPGRT_ATTR_ macros when using
libgpg-error < 1.20.
* common/mischelp.h: Ditto.
* common/types.h: Ditto.
--
Given that libgpg-error is a dependency of all GnuPG related libraries
it is better to define such macros at only one place instead of having
similar macros at a lot of places. For now we need repalcement
macros, though.
We better do this once and for all instead of cluttering all future
commits with diffs of trailing white spaces. In the majority of cases
blank or single lines are affected and thus this change won't disturb
a git blame too much. For future commits the pre-commit scripts
checks that this won't happen again.
