Added Remap_knn.py.test

configure.ac

src/Intgrid.cc

src/Remapgrid.cc

test/data/Makefile.am

test/data/gen_refdata.sh

test/data/temp_remapknn_avg_global_2_to_global_5_ref

test/data/temp_remapknn_avg_global_5_to_global_2_ref

test/data/temp_remapknn_avg_global_5_to_global_5_ref

test/data/temp_remapknn_gauss_global_2_to_global_5_ref

test/data/temp_remapknn_gauss_global_5_to_global_2_ref

test/data/temp_remapknn_gauss_global_5_to_global_5_ref

test/pytest/Makefile.am

test/pytest/Remap_knn.py.test.in