Add another test for #94

This test fails on 64 bits unless the PR #94 (i.e the
0e190eb0424f872997e49b28e73b38091dff4fed commit) is applied.
Travis: use "set -e", so that failures work

See https://github.com/travis-ci/travis-ci/issues/497 for more details why this
is necessary.
Execute the Travis tests from a script

Fixes #98.
Make the test_travis.sh script executable
Travis polishing: use [[ instead of [

And remove unnecessary semicolons.
Merge pull request #97 from certik/add_test

Add another test for #94