moved warp/* into alg/*

git-svn-id: https://svn.osgeo.org/gdal/trunk@26494 f0d54148-0727-0410-94bb-9a71ac55c965
remove warp directory

git-svn-id: https://svn.osgeo.org/gdal/trunk@26495 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_travis_macosx