Merge pull request #462 from thotypous/master

Fix out-of-range page and tweak swipe
page links for crereader and pdfreader
Swipe right will return to previous page or position.
fix no getPageLinks method in djvudocument
tweaks on dimension of dictionary window
fix dogear not shown properly in crereader
adjust nice value of reader.lua process to -2
when launching koreader with KUAL
This should fix #413.
Merge pull request #463 from chrox/master

page links for crereader and pdfreader
basic functionality on file copy/paste/cut/delete in filemanager
There file operations will popup when holding on file entries
in filemanager.
This should implement #244.
Merge pull request #464 from chrox/master

basic functionality on file copy/paste/cut/delete in filemanager
add language setting menu item
update pot templates
Merge pull request #465 from houqp/houqp-master

add language setting menu item