Ignore lib/Attribute, now that Attribute::Handlers is under ext/.
Ignore generated Makefile.PL files for Safe and Attribute-Handlers.
I preferred putting those in specific .gitignore files instead of
ignoring Makefile.PLs in the whole ext/ hierarchy, in order to
ensure a less confusing git behaviour for future generations.
--- /dev/null
+Makefile.PL
--- /dev/null
+Makefile.PL
+/Attribute
/B.pm
/B
/Compress