added formsets to 'edit device form' (dirty version)
added forms displaying in two columns (still dirty)
code cleanups, small bugfixing, eg: multivalues(sn, imei,..) with scroll
moved 'add attachment' after 'additional info'; fixed shared fieldsets bug
reordered formsets according to new spec
Merge branch 'develop' into fieldsets
after review impr. & 'imei' and 'purpose' fields order even improved
Merge branch 'develop' into fieldsets
change default value in backward migration for source
added 'owner' field, reused asset_fieldset instead of defining, added slots to DC
fixed adding part
Merge branch 'develop' into fieldsets
flake8 ready
rm unnecessary lines
Merge pull request #159 from xliiv/fieldsets

Splitted forms to fieldsets