Do not fall back on 'output' when requiring '<aol>.output'

In particular when "cross" compiling for 32-bit in the same directory
as compiling for 64-bit (so that 'mvn deploy' will attach both
artifacts), it is important *not* to fall back onto the 'output'
property when trying to determine the output name of the native
component: the previous run will have added the 'output' property
and the '<aol-64>.output' property so that '<aol-32>.output' does
not yet exist...

This only makes a difference for executables, as they do not want to
have the version suffix that shared libraries and .jar files would
want to have in their file names.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>