Added agreed text from issue #37
Expand on the not recommended CRS with an example

Also caution about "EPSG:4326", which is out there in the wild
and often used improperly.

Also a note about OGR's use of URNs.
Update template.xml
Note that "EPSG:4326" is a historical name.
Merge pull request #39 from geojson/issue37

Added agreed text from issue #37