GTiff: look for .tab file before .wld/.tfw since .tab can contain projection information (and fix doc that wrongly stated that Coordsys was ignored)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27032 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_with_coverage