Add system property for Nokia UI SoftNotification

[gtrxAC]

Added system property to indicate that the implementation supports Nokia UI SoftNotification API. According to Nokia's API docs:

This API is an optional feature in Nokia UI API, and depending on the device capabilities there may be implementations that do not support soft notifications. The System.getProperty("com.nokia.mid.ui.softnotification") will return "true" if this feature is available in the device.

[gtrxAC]

The system properties com.nokia.mid.ui.customfontsize, com.nokia.mid.ui.tactilefeedback and com.nokia.mid.ui.screensaverprevention could also be defined, but I don't know if JL supports these optional APIs. Also com.nokia.mid.ui.version, but again, I don't know what value it should have. Source