Czech language translation fixes

[jsmucr]

cs.po appears to be mainly a product of machine translation, resulting into misinterpretations, terminology inconsistencies, and some hilarious translations in general. Some translations are missing, too.

Given the size of the file, this task will take some time to complete, so for now I'm marking it as a draft. I'll be adding commits as I continue using DT and getting acknowledged with its Czech version.

[TurboGit]

Some notes, you should not merge branch master into your topic branch cs-translation-fixes, you need to rebase.

If this is not something you're comfortable with I'll squash all changes together before merging.

BTW, let me know when this is ready (do not forget to remove the draft status).

You still have 3 weeks to end the translation. TIA.

[jsmucr]

Thanks. I know, I've messed up in the beginning, so I figured that since I have to squash in the end anyway, it doesn't really matter. 😄
It won't be finished nowhere near by the deadline (more likely never) but I'll keep it in mind, and turn this into a single commit and mark as ready ASAP.