depends_test phase is needed

[Anders F Björklund]

Some ports could use a "depends_test" phase, instead of
sticking it in depends_build or even worse depends_lib.

This causes certain ports like py*-cairo to uselessly
pull in heavy ports like py*-numpy (and atlas and gcc*)


"py26-cairo depends on py26-numpy"

distfiles:
port py26-numpy: numpy-1.5.0.tar.gz 2276377 bytes
py26-numpy: 2.2M
port atlas: atlas3.8.3.tar.bz2 2527756 bytes
port atlas: lapack-3.2.2.tgz 4819849 bytes
atlas: 7.0M
port gcc44: gcc-core-4.4.5.tar.bz2 26356188 bytes
port gcc44: gcc-fortran-4.4.5.tar.bz2 1414484 bytes
port gcc44: gcc-g++-4.4.5.tar.bz2 5946112 bytes
port gcc44: gcc-java-4.4.5.tar.bz2 18488619 bytes
port gcc44: gcc-objc-4.4.5.tar.bz2 240383 bytes
gcc44: 50.0M

packages:
2,5M	py26-numpy-1.5.0_1+atlas+gcc44.x86_64.tgz
1,7M	py26-numpy-1.5.0_1+atlas+gcc44.x86_64.txz
6,6M	atlas-3.8.3_4+gcc44.x86_64.tgz
2,3M	atlas-3.8.3_4+gcc44.x86_64.txz
 88M	gcc44-4.4.5_0.x86_64.tgz
 63M	gcc44-4.4.5_0.x86_64.txz

Even though numpy is _only_ used to create test data!


At least with build dependencies (instead of runtime),
you can uninstall them again after building the ports...
Matters more when installing from binaries, but anyway.
http://trac.macports.org/ticket/27369 has the patches

--anders