Increase contrast of fallback tray icons

I'm not sure about other desktop environments, but KDE currently falls back to the default icon set for the tray because the Oxygen icon theme (and probably others) is not compiled for QT5, thus cmst (compiled for QT5) falls back to using the default iconset. See [this stackoverflow thread](https://stackoverflow.com/questions/14880032/native-kde-look-for-qt-5-app) for more.

Currently there is very little contrast between the active and non-active wireless bars in the system tray. For example (this is wl075.png):
![screenshot1](https://cloud.githubusercontent.com/assets/3870410/5173778/47313a70-7423-11e4-80c1-9f064cf29c48.png)

I've created a set of icons for wifi with improved contrast. Let me know what you think. 
![screenshot2](https://cloud.githubusercontent.com/assets/3870410/5173987/3c1d83a8-7425-11e4-9aac-ad51ae822e70.png)