Revises changes and adds some fixes.

@skids' changes are OK, so this closes #1138

Author: JJ

doc/Language/objects.pod6

@@ -835,7 +835,7 @@ role.
 
 =head2 Inheritance
 
-Roles cannot inherit from classes, but they may carry classes, causing
+Roles cannot inherit from classes, but they may I<carry> classes, causing
 any class which does that role to inherit from the carried classes.
 So if you write:
 
@@ -848,7 +848,7 @@ So if you write:
 then C<X::Ouch> will inherit directly from Exception, as we can see above
 by listing its parents.
 
-As they do not use inheritance, roles are not part of the class hierarchy.
+As they do not use what can properly be called inheritance, roles are not part of the class hierarchy.
 Roles are listed with the C<.^roles> meta-method instead, which uses C<transitive> as flag for including all levels or just the first one.  Despite this, a
 class or instance may still be tested with smartmatches or type constraints
 to see if it does a role.