[FIX] mail: escape user and partner names before being rendered in mail widgets
[FIX] some other t-raw to t-esc conversions
[FIX] audittrail: fixing various bugs

iter only on fields on __all_columns, this avoids getting inexistant fields such as 'in_group_42' for res.users
make sure read method calls works when passing only one id (lp:1214149)
when itering on change values, if different model (eg: if field is o2m) make sure make name_get on the model of the field and not on the parent model
[FIX] qweb templates: t-raw to t-esc

t-raw usage is discourage if not to displayed html content (after escaping) as it may contain unsafe data
[FIX] auditrail: in case of unlink retrieve first the record and then execute the unlink (the other way around is causes problems for name_get...)
[MERGE] [FIX] audittrail: various bugs (opw 603072)

- tracking unlink does not fail anymore
- do not track virtual fields on res.users model (would for .column call)
- make sure read calls with one id works (launchpad bug lp:1214149)
- select the correct model when tracking x2m fields values