HIG cleanup #2

`cs_effects.py` now (de)sensitises the options based on whether effects are at all enabled.

![screenshot from 2013-07-24 02 17 06](https://f.cloud.github.com/assets/179487/847470/e9a2d4d2-f43e-11e2-9a93-84b5136f1151.png)

Headings introduce new i18n strings, is there a place we collect these changes for TL teams to review? Additionally, the strings need context marking, "Miscellaneous" on its own is a rather crappy string to translate. So this should be something like `_("Effects settings|Miscellaneous")`. Unless it binds the domain per c-s module?