Filesearcher: added notification for no results
add unit tests for readerdictionary and readerhighlight
fix dictionary spec
Refactored menu

While looking into #1219 I accidentally ended up refactoring some stuff.

Tested in emulator and on H2O, but be wary because I might have overlooked something.
Merge pull request #1227 from Frenzie/master

Fixed spaces stripped out by Transifex in readerui.lua by using util.template
Merge pull request #1226 from Frenzie/filesearcher

Filesearcher: added notification for no results
Merge pull request #1225 from Frenzie/language

Refactored menu
Merge pull request #1224 from chrox/cover_60

add unit tests for readerdictionary and readerhighlight
wait for background thread before free()ing koptcontext

This should prevent freeing resources that are actually in use in
a background thread.
Merge pull request #1228 from hwhw/fix_koptcontext_free

wait for background thread before free()ing koptcontext