Reverse meaning of binary sensor_flag in composites and mosaics, set missing_value to 0

[mliukis]

• Modify composites code for the sensor_flag:
  • Reverse the meaning of 0 and 1: 0 - included, 1 - excluded. This will allow for more intuitive display of data to the end users in QGIS.
  • Set missing_value to 0 instead of 255. This is to allow for uniform display of masked out high noise areas

Write scripts to fix existing data:

• Composites
• Mosaics