[postgis-devel] Steps toward out-of-tree builds

[Sandro Santilli]

With dd4ab0d780092be3e5c31172f54afeff96255b37 I pushed a good amount
of changes in our build scripts aiming at supporting out-of-tree
builds. It actually works, so far, in *building*:

  mkdir build; cd build; ../configure && make

It'll need more work: I didn't test a build dir being in a different
hierarchical relation with the actual source tree and unit tests relying
on external resources are currently failing to find their files; but
it's a good first step.

Please make your tests and if you wrote a testcase which you find is
using external resources please help extending it to accept a
parameter as to where such resources would be :)

The related Trac ticket is here:
https://trac.osgeo.org/postgis/ticket/5060

Happy building !

--strk;