Merge pull request #232 from chrox/master

patch crengine to register external fonts
Add InputText:setText and avoid non-intuitive UI behavior after light toggle
Merge pull request #233 from thotypous/fl-toggle-clear

Add InputText:setText and avoid non-intuitive UI behavior after light toggle
Update koreader-base
Merge pull request #234 from thotypous/master

Update koreader-base
disable path compress on relative path
fix: reset current page on item_table switch for menu widget
Merge pull request #235 from houqp/houqp-master

reset current page on item_table switch for menu widget
Change util.isEmulated to boolean and fix frontlight

Device:hasFrontlight always returned a true-like value because util.isEmulated was an integer.
Fixed this, also, used a polymorphic object design to reduce FrontLight code, and
adapted BaseFrontLight for the emulator.
Merge pull request #236 from thotypous/frontlight-fixes

Change util.isEmulated to boolean and fix frontlight
Fix crash when trying to go to / on FM

Deals with more cases in FileChooser:compressPath, including `/mnt/..`.
Merge pull request #237 from thotypous/fix-crash-root

Fix crash when trying to go to / on FM
Remove FileChooser:compressPath, use util.realpath
Use ReaderFrontLight:addToMainMenu in FM

Check if frontlight is present using the same method as ReaderFrontLight:init,
just for consistency.
Merge pull request #238 from thotypous/realpath

Realpath
add hidden file toggle
Merge pull request #240 from houqp/houqp-master

add hidden file toggle for file manager
Update documentation

Since the build system has changed after modularization. Also,
point out that the project now supports Kobo devices too.
Merge pull request #250 from thotypous/master

Update documentation