fix cross-compilation issue with Numpy
reorder the if's for clarity
All installed files marked with component names for install customization.
Initial Linux packages build rools for CPack.
fix GpuMat::copyTo method with mask:

fill destination matrix with zeros if it was reallocated
Merge pull request #2181 from asmorkalov:ocv_packaging
fix message sent to user during cross_compilation
Merge pull request #2175 from vrabaud:2.4
Merge pull request #2188 from jet47:gpumat-copyto-fix
removing duplicated legacy license, the actual instance is in 'opencv/LICENSE'
Merge pull request #2193 from apavlenko:2.4_lic_remove
Improvements in package build.
Merge pull request #2197 from asmorkalov:ocv_packaging2