Improve ogre 1.x ThermalCamera to match ogre 2.x's implementation

[iche033]

Desired behavior

The ogre1.x thermal camera implementation is missing a few features that are available in ogre2:

• color based temperature variation
  • related ogre2 PR: Add temperature variations to thermal camera readings based on color #211
• support changing resolution/min/max at run time:
  • related ogre2 PR: Fix user settings of thermal camera being ignored #1138
    • more info in issue: Thermal camera does not react to updated settings once thermal texture has been created #1134
• 8 bit + resolution support
  • related ogre2 PR: Add support for 8 bit thermal camera image format #235

Implementation suggestion

The pull requests above show these features in ogre2. We need to port them to ogre1.x.

• Here're ogre1.x's material script and the fragment shader for the thermal camera.