[mythtv-users] Branch differences?

[Ismo Tanskanen]

Sorry about newbie question, but what are differences between mythtv 
branches?

If I look at svn download area I see:

​auto-configuration
​commdetector2
​commflagging
​multiuser
​mythexport
​mythmusic-ui
​mythtv-channel-scan
​mythtv-eit
​mythtv-multirec
​mythtv-pip
​mythtv-qt4
​mythtv-vid
​mythui
​mythweb-ui
​release-0-18-fixes
​release-0-19-fixes
​release-0-20-fixes
​settings-revamp
​softpad
​themestringstool

Then there is trunk version. I understand -fixes versions, multirec and 
trunk, what apparently is latest code?
But what are those else? Is there any good description about branches? 
And major differencies on 0.18 , 0.19 , 0.20 and trunk versions?

Thanks,
-Kane