add: easier access to all envelope fields in mapping

[GoogleCodeExporter]

the bots mapping script typically handles one 'message'.
I want an option to access and fill all envelope fields from the mapping.

for incoming:
inn.envelope: a dict with all fields from envelope (UNB or ISA/GS).
best way to fetch: inn.envelope.get('ISA05') (get either value or None)

for outgoing:
out.envelope: a dict with all fields in envelope.
- the enveloping process stays the same (group by sender, receiver, etc)
- if messages in same envelope: use envelope of (first, last, one of) messages. 
For now: have to store this 'somewhere' (eg in persist).

Original issue reported on code.google.com by hjebb...@gmail.com on 20 Apr 2015 at 3:59

[GoogleCodeExporter]

access only (fill is really different).
related:  Issue 328: pass frommail and tomail to mapping

Original comment by hjebb...@gmail.com on 21 Apr 2015 at 4:46

• Changed title: add: easier access to all envelope fields in mapping

[GoogleCodeExporter]

did that for x12, edifact, tradacoms.
remarkably easy.....should have done that before ;-))
in inn.ta_info:
'ISA05': 'ZZ'
'ISA15': 'P'
'ISA10': '1444'
'GS04': u'20141231'

Original comment by hjebb...@gmail.com on 22 Apr 2015 at 10:09

• Changed state: Fixed