[REF] html_email_clean: refactoring of the algorithm, now better taking into account hotmail / msoffice emails. Added tests.
[IMP] html_email_clean: now handles maximum character number truncature.
[REF] html_email_clean: refactored the algorithm to clean it, specifically about truncature. Now add classes to node when not removing them, to be managed by the web client.
[MERGE] Sync with trunk
[MERGE] Sync with trunk
[MERGE] Sync with trunk
[DOC] Added change in changelod.
[TESTS] tools: mail: added some tests + some cleaning in tests
[MERGE] [IMP] tools: improved html_email_clean :
- improved heuristics to find a quote, added MsOffice / Hotmail specific heuristics
- added an option to shorten the html, adding the 'read more' link
- it now flags nodes to remove; an option to remove them has been added.

This improvement allows to display a shortened and cleaned version of emails in the chatter, with a 'read more' link that displays the full email. See the addons branch for more details.

[TESTS] Added tests, based on cases that fails with the previous implementation