The ext_typoscript_setup.txt files sometimes don't get included
Bug in t3lib_tstemplate::addExtensionStatics():
When the template having the "rootlevel" flag is not the same as the template having the "clear constants" and "clear setup" flags, the ext_typoscript_setup.txt and ext_typoscript_constants.txt don't get included.
The condition if(...&&$row['root']) should be changed to if(...&&$row['clear']&1) for the ext_typoscript_constants.txt inclusion and if(...&&$row['clear']&2) for the the ext_typoscript_setup.txt.
(issue imported from #M2747)