If only one result file is specified, just print all the tests
followed by the outcome.  For example:

fbo/FBO blit from missing attachment: pass
fbo/FBO blit to missing attachment: fail
fbo/fbo-1d: pass
fbo/fbo-3d: crash
[...]

If multiple result files are specified, we'll print pass/fail/etc
for each file.  Example:

fbo/FBO blit from missing attachment: pass pass
fbo/FBO blit to missing attachment: fail pass
[...]

If -s (--summary) is specified, only print a summary of the number of
passes, fails, crashes, etc.

if -d (-diff) is specified with multipe result files, only print the
tests which had different outcomes.  Good for spotting regressions.

v2: fix -l option issues

Reviewed-by: José Fonseca <jfonseca@vmware.com>