Rename 'dring' occurrences to 'jami'.

Automated via:

  $ git grep -l dring | xargs sed -i 's/dring/jami/g'
  $ git ls-files | xargs sed -i 's/Error : jami/Error : jamid/g'

Then some changes by hand to adjust jamiId into fileId, and jami_info
into transfer_info.

Change-Id: Ic0be8fe918a2d9eb52e28d598ee4581db245674f