add-header: default to handling all .java files in cwd and its subdirs
add-header: default to handling all .java files in cwd and its subdirs

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

This used to be revision r4914.

TehSAUCE/imagej,TehSAUCE/imagej,TehSAUCE/imagej,biovoxxel/imagej,biovoxxel/imagej,biovoxxel/imagej