#3 Note and checklist export

[Aleksey Frolovskiy]

User should have a possibility to export notes and checklists in text files with UTF-8 encoding.

How it should work in general:
I. I open the folder which contains the note or checklist I want to export.
2. I choose that note/checklist and press "Menu", then press "Export it"
3. A phone's file system browser appears where I can choose the folder I want to export it to.
4. I press OK and note/checklist saves as file.

Checklists should transforms into text like this:
[ ] unchecked item
[x] checked item