countdown shortcuts
Merge pull request #1230 from ostcar/countdown

Countdown shortcuts
Fixed #1197: Use big heading for custom slides without text.

Keep last projector scale/scroll values after activate new slide.
Added global chatbox for managers.
Improved chatbox style. Updated jquery cookie and jquery ui.

- Fixed js error on dashboard page if no cookie is found.
- Use cookies only until end of session. For dashboard cookies use url /dashboard only.
- Updated permission numbering of builtin groups and added can_use_chat permission.
- Used minified version of jquery.cookie.
- Added TODO comment for django session way from pull request.
Merge pull request #1220 from emanuelschuetze/chatbox

Chatbox (Fixed #504)
Merge pull request #1221 from emanuelschuetze/fix-1197

Fixed #1197: Use big heading for custom slides without text.
Update English translation files.
Merge pull request #1255 from normanjaeckel/TranslationEnglisch

Update English translation files.
Updated packages in requirements_production.txt and prepare_portable.py

Added new license files of packages for portable version.
Fixed #1240 (No assignment poll form fields for votes invalid and votes cast)
Fixed #1102 (New config option to set percent base for polls)

Use locale format for poll percentage decimal number.
Merge pull request #1256 from emanuelschuetze/portable

Updated required packages and portable
Use right projector logo (as in stable/1.5.x branch).
Merge pull request #1248 from emanuelschuetze/fix-1102

New poll config option for 100% base (fixed #1102 and #1240)
Merge pull request #1257 from emanuelschuetze/projector-logo

Use right projector logo (as in stable/1.5.x branch).
Updated English language files.
Merge pull request #1259 from normanjaeckel/Translation

Updated English language files.
New poll slides for motion and assignment. (Fixed #862)

Move result table from assignment slide to assignment poll slide.
Use "result" in singular for motion and election results.
Merge pull request #1232 from emanuelschuetze/pollslide-862

Pollslide for motion and assignment (Fixed #862)