wizard: make the custom search case insensitive

Closes #251

Signed-off-by: Jakub Filak <jfilak@redhat.com>
localization: fix gettext

https://www.gnu.org/software/gettext/manual/html_node/Libraries.html

Related to rhbz#1087861

Signed-off-by: Jakub Filak <jfilak@redhat.com>
Merge branch 'gettext_for_libraries'
Merge branch 'gh251_case_insensitive'