Handle huge /bin directories in libdb2 test

Handle huge /bin directories in libdb2 test

The test suite for libdb2 uses /bin as a source of filenames and
contents for insertion into databases.  Fedora 17 (and possibly other
OSes) have /bin symlinked to /usr/bin, which can vastly increase the
number of files found, exceeding some limits of the test databases.
Truncate this list of files at 100 to prevent this problem.

ticket: 7201 (new)
status: pullup
target_version: 1.10.3