add auto cache option to category model
set version number to v2.3.0
finish thumbnails' settings
add qrcode to welcome page
finish feature/thumbnail
add http basic auth feature
add login throttle
edit changelog
add qrcode on install page
fix bug
edit changelog
warn users if they don't have php imagick extension
make footer looks better
Merge pull request #38 from DiliCMS/feature/v2.3.0

Feature/v2.3.0
Merge pull request #39 from DiliCMS/develop

Release v2.3.0