Add and use i2c addresses, d4xx cleanup, rs_viewer minor update

[xzhangxa]

d4xx: Define i2c addresses and cleanup

• Define missing i2c addresses as macros;
• Use the addr macros;
• Cleanup stream on/off and configure code, not only to reduce lines but also make later IMU addition much cleaner.

rs_viewer: updates

• Checks whether pixelformat setting successful;
• Properly exit when streamOn fails.

On top of #66