add: GDAL logo and readme refactored
converting readme to markdown
add: ignoring Windows thumbnails files
fix : relative pahs to images
fix: path to GDAL logo
add: link to page presentig complete list of softs using GDAL/OGR
add:  commands to install on Ubuntu and link to GeoTribu tutorial
fix: rst syntax
little fix
add: Python recipes
verbage fixes
Merge pull request #1 from Guts/master

First step to enhance French doc