Rework notice boxes

[McShelby]

This patch includes the following:

• translatable labels (Notice headlines always in English #334, A way to make a notice multilingual #128)

  I grabbed translations from here. If not available, I put in the old english text. To all foreign speakers: Please review!

• multiple blocks in one box (notice shortcodes - multiple lines/layout #402, Notices ignoring the lists #152)

  Because I had to change the CSS for the first topic significantly, I also included this fix.

• usage of distinct icons for each type

  This is to improve readability for color blindness and on black/white printouts.

• switching colors for info and note

  This is because internationally the i symbol is usually associated with a blue background.

After rework, it is now easier for theme users to overwrite just the colors and icons of the notice boxes in their own CSS.

[dahlsailrunner]

Is there a timing on getting this change merged? I got here by trying to figure out how to to more than one paragraph in a notice and it seems like this merge will be the answer. Thanks in advance. :)

[m-czernek]

+1, notice shortcode is not usable for multiple lines.

[dahlsailrunner]

For anyone else looking to create note content that is more than one line (can include bulleted lists, etc), just take the changes in layouts/shortcodes/notice.html and static/css/theme.css and apply them to the corresponding files in your local project. Worked like a champ for me.

Good work and thank you for the change @McShelby ! :)