Made generated ids for functions and overloaded functions human-readable
which also results in (mostly) human-readable names for
their .html output files. Made generate.id template properly use
its node parameter (merge of parts of revision 41461 from sandbox/boost_docs).
Made class name in synopsis a link to class reference page, which is useful
for nested classes (merge of revision 41435 from sandbox/boost_docs).
Removed spurious new line in synopisis between a nested class
and the comment describing its purpose (merge of revision 41434 from
sandbox/boost_docs).
Added a warning if an "inherit" element has
no "type" child element (partial merge of revision 41463 from
sandbox/boost_docs).
