Interim commit and work in progress on CrossInSAR operator
Methods and refactorings of CrossGeometry class, for its use in NEST Operators

 - polynomial estimation for both jLinda and NEST/BEAM/JAI resampling semantics
 - clean up and more info in unit test
Interim commit of Cross InSAR operator

 - first version of operator, help, UI, etc....
Re-commit because of messy merge: Mission / Sensor field in SLCImage()
Rework of LUT class

 - clean-up and refactoring, can be inherited...
 - normalization of kernels controlled through flag
Removed unnecessary Enum of kernels from LUT class
SimpleLUT - Simplified interpolation Look-Up-Table

  - Convenience class, no normalization, and advance methods,
  - Methods designed having in mind interfacing to JAI,
  - Used for code clean-up of NEST depending on jLinda.
Quick clean-up to use refactored method names
Fixes to reflect changes of semantics of Cross InSAR Geometry

 - Semantics set to: OFFSET = (SLAVE - MASTER)
Clean-up of Cross Geometry Tests: New Semantics

 - changes for (offset = slave - master) semantics,
 - working with MHz as units for RSR,
Work on Cross-Resampling Operator: almost there...

Notes:

 - This builds on JAI, not on jLinda internal implementation,
 - Operator crashes depending on size of source/target product: eg it goes
   up to last row of tiles, and than it crashes
 - Crashes probably related to inconsistent implementation of
   BorderExtender in getSourceTile in some library, either JAI or NEST, or
   I am using the call incorrectly.

ToDo:
 - Merge in methods for updating of metadata from not-public branches.