FixesHomebrew/homebrew#10559.
Also added missing deps for osm2pgsql.
Removed some ACLOCAL_FLAGS stuff as in theory this is not set in ENV.rb. Would like to see if it causes trouble. Should just work now.
Replaced ENV.gcc_4_2 + comments with calls to "fails_with_llvm",
to specifically message to the user when a formula is known or suspected
to not build with LLVM. If the user specifies "--use-llvm", the message
will be displayed, but compilation will be tried anyway.
Since using LLVM is now an advanced/hidden feature instead of the
default on 10.6, we'll let the user try anyway (and submit patches
if things are now working.)
So many tools expect all SDL modules to be installed in the same place. So we have to change the prefix path to HOMEBREW_PREFIX. This is probably the correct thing to do in general in fact.
brewkit.rb changes ENV destructively, so lets not do that everytime a formula
is required. Now it's possible for other tools to require a formula
description without worrying about side-effects.
Mac OS X projects that use SDL through Objective-C may
require the "SDLmain" support files.
Since these are not strictly header files, they are not
installed into include by default, so we put them in our
libexec folder.
