Fix - typing on a C++ inher-intro or inher-cont line should preserve the

Fix - typing on a C++ inher-intro or inher-cont line should preserve the
fontification of the inherited class names.  Analogously for namespace
names and Java import, extends, etc.

(cc-fonts.el): (c-make-font-lock-BO-decl-search-function): New function.
(c-basic-matchers-after - "Fontify the clauses after various keywords"):
Extract the three keyword lists for the 3 erroneous constructs from the
list of four, and use the new function above in place of an old one.