Merge pull request #444 from chrox/master

tweaks on default page margins with new punctuation calculation
Merge pull request #445 from chrox/master

fix an infinite loop when upskip a left punctuation
Avoid off-limits dictionary title and make font size adjustable
Merge pull request #447 from thotypous/master

Avoid off-limits dictionary title and make font size adjustable
Update readerscreenshot.lua

This adds screenshot functionality for the Kobo Aura. 

The pam-files generated can be read and converted using Imagemagick for linux/windows.

I've added the infomessage because it takes 5+ tries to get a screenshot by tapping the lower left and upper right corners. The other diagonal is not working for the Kobo Aura yet.
Update readerscreenshot.lua

No the first part of the text can be translated.
Merge pull request #449 from Markismus/patch-3

Update readerscreenshot.lua (Kobo_phoenix)
Merge pull request #451 from chrox/master

clear temp highlight when turning page
add goto link function for CreDocument
refactoring widget registering in readerui
update koreader-base
add missing readerlink widget