Create a simplified database file out of the calibre file

Makes searches WAY 100 times faster.
From the second run on.
Update filemanagermenu.lua
Code cosmetics
Default Settings finally also with the array fields
Merge pull request #817 from WS64/master

Create a simplified database file out of the calibre file
remove rescaleByDPI since it's not reversible
alternatively we store the original size before scaling by screen DPI
and use that value when needed.
enable Wikipedia support
Since wikipedia server is language specific we should first detect
language of the text by querying Google Translate. Make sure you have
access to both Google Translate and Wikipedia service to use this
function.
fix tap on word title will crash koreader
long press the backspace key will clear input text
Just save settings that really were changed

And not also settings that are different from the ones loaded.
This prevents Koreader from overwriting your complete persistent.defaults.settings when you started Koreader with a malformated persistent.defaults.settings file and choose "save settings". In such a malformated case you just can edit the damaged setting and save it back (although you can't see which one is damaged since the defaults settings are taken)
To edit arrays we need { and }

I removed pi and e and two other characters that were there twice and replaced them by {, }, [, ]
Merge pull request #819 from WS64/master

Add { and } to cirtual keyboard and just save back settings that really were changed
update pot file
prompt users to turn on Wifi in OTA update and Wikipedia lookup
fix koboEnableWifi
Bugfix. Latest version just allowed you to enter the editor once
fix missing declaration for symbol 'munmap'
Merge pull request #820 from WS64/master

Bugfix. Latest version just allowed you to enter the editor once
strip punctuations in word before wikipedia lookup
use original lookup word in wikipedia lookup