* Localize strings used in widgets (using gettext and locale)
* Remove redundant code, e.g:
  * various internal utility methods (e.g. to_string) - move to separate utility module
  * use inheritance to centralize code because there's too much copy-paste coding:
    * initialization code (extract abstract LdapView and LdapSelector superclasses and handle common initialization stuff over there)
* Make variable naming more consistent