Documentation updates to filters.xml
Add to __ShowStatusMessage__ examples

Show how messages can be lost if status messages are too long.
Samples.xml ordering and documentation

Minor documentation changes.  On several items that do many mappings,
moved the code of the mappings close to the documentation (appendix
tags).  This means one sees (appendix, mapping, blank line) for each
mapping instead of trying to puzzle out which code goes with which
mapping.