Removed not necessary matrix initialization in PolyUtils.polyFit2D()
Clean up of logging in PolyUtils, logger level set to 'warn'
Cross InSAR functionality - jLinda core classes

 - core class computes the (dummy) coregistration polynomial based on ratios
   between original and target sampling frequencies

 - prototype implementation is in unit test

ToDo: see code for details.

Note: Since everything is deterministic PolyUtils.polyFit2D is used in the estimation
of polynomial. No need for data-snooping and outlier removal. This is quite straightforward
and efficient.