Attributes that should clear xslate don't

[madsen]

The documentation says that attributes that are passed along to the Text::Xslate constructor cause any previously-constructed Text::Xslate object to be cleared. But you left off the trigger that does the clearing from some of the documented attributes.

In particular, I noticed line_start, tag_start, tag_end, warn_handler, die_handler, and pre_process_handler all have this problem. There might be others I missed.