Fix pluralized forms and whitespace in translations and fix the l10n tools

The plural forms are different from english in most languages so one has to use ngettext to provide proper forms to translators.

For the whitespace, the gettext is fragile so you have to not put any weird witespace.

The utils update just cleanup your gettext usage to be more straingt-forward and not breaking translation headers and thus borking the plural forms mentioned above.

In the pullrequest I also updated more czech strings and reverted weird czech updates which I incorporated into my translation where required.

And in last commit I refreshed all translations to utilize the new plural forms.

PS: if you get more czech updates just feel free to add me to the review and I will write hints/comments for the translator as it is easier than reverting and fixing all the typos myself :-P