Bumped sphinx version to 1.2 (stable)

Signed-off-by: Ivan Habunek <ihabunek@apache.org>
LOG4PHP-205: Avoid warning when getting location info

debug_backtrace() sometimes does not return 'file' and 'line' values. So
check if they exist before using them.

Signed-off-by: Ivan Habunek <ihabunek@apache.org>