tree 7e5d1969c241556cef74e130a4d2118771dc61b6
parent 78d1fd07d27a2ac28eca792933e052cb1fe1fa17
author David Klempner <klempner@imsanet.org> 1423073939 -0800
committer David Klempner <klempner@imsanet.org> 1423073939 -0800

Fix up feature test macros

Move all feature test macros to the start of the file and check that
they aren't already defined or defined to a lower value than the file
needs.

Projects should be allowed to put these in CFLAGS and we shouldn't break
when they do.