.lla files are media files and not text

[pombredanne]

Following #419 , some .lla files such as pyproj-1.9.5.1/datumgrid/alaska.lla do timeout. Originally from https://github.com/jswhit/pyproj and created with http://proj4.org/

These are text files containing geographic/cartographic "grid" data: See

• https://github.com/OSGeo/proj.4
• http://proj4.org/grids.html#grids
• http://lists.maptools.org/pipermail/proj/2008-February/003294.html
• http://osgeo-org.1560.x6.nabble.com/proj-datumgrid-git-repository-td5293433.html