Cli gettext script

Adding script to /cli and also to katello-cli.spec
The script checks for malformed gettext strings with multiple placeholders.
Also fixed malformed gettext found by the script.
Merge pull request #1525 from jhadvig/cli_gettext_script

Adding script to /cli and also to katello-cli.spec
The script checks for malformed gettext strings with multiple placeholders.
Also fixed malformed gettext found by the script.