Deprecation

- Removed deprecated 'fg:' and 'bg:' attributes, which involves code,
  documentation and tests.
- Cleaned out NEWS file.
- Cleaned out config import synonyms, which should have been deleted a while
  ago.
- Removed unused localized strings, but left the 'deprecated' one behind,
  because it will be needed.

src/Config.cpp

@@ -300,22 +300,6 @@ std::string Config::_defaults =
 	"#merge.default.uri=user@host.xz:.task/         # URI for merge\n"
 	"#pull.default.uri=rsync://host.xz/task-backup/ # URI for pull\n"
 	"\n"
-  "# Import heuristics - alternate names for fields (comma-separated list of names)\n"
-  "#import.synonym.bg=?\n"
-  "#import.synonym.description=?\n"
-  "#import.synonym.due=?\n"
-  "#import.synonym.end=?\n"
-  "#import.synonym.entry=?\n"
-  "#import.synonym.fg=?\n"
-  "#import.synonym.id=?\n"
-  "#import.synonym.priority=?\n"
-  "#import.synonym.project=?\n"
-  "#import.synonym.recur=?\n"
-  "#import.synonym.start=?\n"
-  "#import.synonym.status=?\n"
-  "#import.synonym.tags=?\n"
-  "#import.synonym.uuid=?\n"
-  "\n"
   "# Aliases - alternate names for commands\n"
   "alias.rm=delete                                # Alias for the delete command\n"
   "alias.history=history.monthly                  # Prefer monthly over annual history reports\n"