Merge bash tests into Perl infrastructure

Sorry, I did not notice that you already had a integration test infrastructure in place - I have now merged the bash functionality into the Perl script and moved it to tests/normal.pl (reverse.pl to come). I have also made the tests callable from the top-level directory using just "make test" (or "test-verbose").

    ~/encfs$ make test
    perl -MTest::Harness -e '$Test::Harness::verbose=0; runtests @ARGV;' tests/*.pl
    tests/normal.pl .. ok     
    All tests successful.
    Files=1, Tests=100, 12 wallclock secs ( 0.03 usr  0.00 sys + 12.05 cusr  0.11 csys = 12.19 CPU)
    Result: PASS

Also, I thought the readme should mention the features EncFS has that are not found elsewhere to (possibly) attract more developers.