How to activate USB mass storage and developer options on CyanogenMod

For over three years I’m a user of Android smartphones. At first with Motorola Defy, then Samsung’s Galaxy S2. What both of these devices have in common, is the fact, that both were not running the original ROM for a long time. Too much trash, too much unnecessary, pre-installed software and really to less updates.
Both devices got the CyanogenMod-ROM, one of the most famous mods for Android devices. And because I like to be up to date and also like to try out experimental features, I flash my Samsung Galaxy S2 regularly with the so called nightly builds. (Nightly-Builds = daily updated version directly from the developers. Bleeding edge but not always 100% stable.)
With the latest CyanogenMod version (10.1), two features have disappeared, so far. On the one hand the possibility to use the phone as a mass storage device on your PC and on the other hand menu item […]