Added several ultrasound processing tools for UFF

[androst]

Added several ultrasound processing tools for the UFF format and some modifications of existing code:

• Scan converter
• Log compression
• Normalization of dB data
• Some of the functionality is extracted to a separate reader object

Essentially, this should allow passing non scan converted data in the uff format. Works with new UFF viewer for both scan converted and non scan converted data.

[smistad]

Tested and seems to work fine, well done. Only issue was that playback slider in UFF viewer was broken after this update. Issue is that getNrOfFrames can now only be called after calling update on UFFStreamer, I quick-fixed it by moving the slider setRange in the UFF viewer.

Ideally I would have wanted the envelope, log compression and scan conversion routines in separate process objects, so we could use them with other data streams than UFF, such as clarius and GE, which now can stream non-scan converted data in real-time. Also, the UFF streamer now loads all frames into memory at start which defeats the purpose of a streamer. But that will be a task for the future when we have time.