Collective.dms.mailcontent

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- Added in EmailAttachmentsVocabulary related files of linked mails (reply_to)
[sgeulette]
- Improved reply form to initialize reply_to widget with incomingmail reply_to values
(including backrefs). Do not include deeper refs.
[sgeulette]

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- Use interface to ckeck context in validateIndexValueUniqueness
(multiple types can use the same interface).
[sgeulette]
- RelatedDocs field (reply_to) use now object_provides criteria
[sgeulette]
- Replaced portal_type test by schema interface providedBy test
[sgeulette]
- Added IOutgoingEmail and IFieldsetOutgoingEmail schema interfaces to describe
email information
[sgeulette]
- Added external_reference_number index
[sgeulette]

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- Reply form: added im treating_groups in om recipient_groups if another group responds
[sgeulette]
- Added tests on reply form
[sgeulette]

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- Correction when setting form values: no more change after form edition.
[sgeulette]

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- Use a separated method to update reply fields (reused in batchactions form)
[sgeulette]

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- Renamed sender and recipients indexes.
[sgeulette]