Depending on the distribution, binaries or shared libraries a test is
dependent of may not be stored at the same place.

This patch introduces the ability to define option in the dependency
list, by separating the optional target names by a '|' character.

For instance the dependency of test may be described this way:
{'flavor': 'ns', 'deps': [ '/bin/foo|/usr/bin/foo' ], 'flags': 'suid'}

Note, there shouldn't be any spaces around the '|'.

If none of the optional dependency is satisfied, an error is raised.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>