Fixed some issues with the --export-map command line

* Actually work when the format is not explicitly specified, instead
  of spitting out an error message
* Avoid quotes in the output
* Put the translated strings in an appropriate context
* Indicate the optional "format" argument in the help text
* Remember to delete the tilesets
Raised version to 0.11.0 and updated NEWS file
Updated translation files

Running 'make ts' in the 'translations' directory.

36 new strings, 695 strings total.