assertTrue does not work with "set -e" about shunit2 HOT 3 CLOSED

The problem in this case was the shunit_match_=`expr "${shunit_condition_}" : 
'\([0-9]*\)'` which returned a 1. i attached an || true to ensure that return 
value is always 0 (since it won't be evaluated by the script).

I also fixed the problem for the AssertEquals and AssertNotEquals functions. 
there the problem came frmo failNotEquals.

One remaining problem is that an `assertTrue 1` will still cause the crash 
since the assertion function returns failure in this case. I'm not sure if this 
is a responsibility of the assetion function or the caller that should check 
the return value. I tend to give the responsibility to the caller.

I did not write test yet because I'm not sure how this behaviour could be 
tested.