debian/changelog: s/UNRELEASED/unstable/
Update Changelog.

Using output of
git log 0.16.0..HEAD
--pretty=format:"%ad  %an  <%ae>%n%n    %s%n    %b" --date=short
Remove some spurious Image (i.e. PIL) imports.
s/ui/ui_string/ fix in a couple of files.
Remove some spurious imports from recindex.py.
Remove some obsolete code checking for old gtk versions.
Small fix to ui/catalog/README.
In Batch Editor, replace "Servings" by "Yield" and "Yield Unit" rows.

Fixes #332.
Translate attributes in batch editor's confirmation message box.
Fix batch editing of categories.

Fixes 333.
Update *.po[t] files.
Only set_current_folder if get_user_special_dir(USER_DIRECTORY_PICTURES)
isn't None.

Fixes #725
In PDF export, print title only once (as heading).

Fixes #258
debian/patches/changelog, debian/patches/series: Remove (fixed upstream).