[FIX] Making app_tests.py more robust and info more useful
[FIX] Making app_tests.py more robust and info more useful

 * removing empty strings from arguments
 * printing exception stack trace


git-svn-id: a7f2a8f7432d210e972fb03898013d213e2b549b@13843 e6417c60-b987-48fd-844e-b20f0fcc1017

gkno/seqan,gkno/seqan,gkno/seqan,gkno/seqan,gkno/seqan,gkno/seqan,gkno/seqan