Merge pull request shadowsocks#635 from x1596357/fix/data-usage-not-a…

…utomatically-updated

Update data usage in real time

Make use of unique_ptr

Mark v2.9.0

Bump version for release

Bump requirement for libQtShadowsocks

ready to release 2.6.1

mark new version

ship new version

mark version 2.5.0

mark 2.4.2