Previously, I used a shell script to extract modification date ranges
from the Git history, but that was complicated and unreliable, so now
every file just gets the same year range in its copyright header. If
someone needs to know when a specific file was modified and by whom,
they can look at the Git history themselves; no need to include it
redundantly in the header.
Rather than try to support mixing Avian's core classes with those of
an external class library -- which necessitates adding a lot of stub
methods which throw UnsupportedOperationExceptions, among other
comprimises -- we're looking to support such external class libraries
in their unmodified forms. The latter strategy has already proven
successful with OpenJDK's class library. Thus, this commit removes
the stub methods, etc., which not only cleans up the code but avoids
misleading application developers as to what classes and methods
Avian's built-in class library supports.