New port: postgis2 (PostGIS 2.0)

[vincent habchi]

Hi Puneet,

>> I’ve committed this morning in r92462 a new port corresponding to PostGIS v 2.0 and up.
>> This port is incompatible with postgis, that is to say PostGIS 1.x. Both install the same files at the same place.
> 
> 
> Hmmm... That's a deal breaker for me. I don't have two machines to test it out. Since the two different versions can haooily coexist, why not make it so instead of requiring uninstalling PostGIS 1.5?

Because PostGIS 2.0 won’t compile with PostGIS 1.5 installed. There are several include files that PostGIS 1.5/2.0 installs in ${prefix}/include that take precedence over the ones furnished with the distribution (because -I${prefix}/include appears before other -I… during compilation). Thus, if you have PostGIS 1.5 installed, PostGIS 2.0 will mistakenly use the already installed headers to compile and fail.

Besides, I am not sure that the libraries installed by PostGIS 1.5 and PostGIS 2.0, albeit bearing the same name, have the same API.

Vincent