examples

Most edits are about harmless errors in comments, but there are also
some some strings in code:
 generator/mavgen_javascript.py
 generator/mavgen_javascript_stable.py
 mavwp.py
and in tests:
 generator/javascript/test/mavlink10.js
 generator/javascript/test/mavlink20.js
 generator/javascript_stable/test/mavlink10.js
 generator/javascript_stable/test/mavlink20.js