Boost libs: cflags + ldflags should be empty

[kkaefer]

The compiled boost libs are static libs, so the user should use static_libs to obtain the paths. However, calling cflags and ldflags on them currently either fails, or returns -lboost_*, which may cause failure since it doesn't specify the path to the library also.

We should mass-apply this patch to all compiled boost libs:

diff --git a/script.sh b/script.sh
index b2eb041..e5562b2 100755
--- a/script.sh
+++ b/script.sh
@@ -58,8 +58,12 @@ function mason_compile {
     mv stage/${MASON_LIB_FILE} ${MASON_PREFIX}/${MASON_LIB_FILE}
 }

+function mason_cflags {
+    : # Use the boost headers package
+}
+
 function mason_ldflags {
-    echo "-lboost_${BOOST_LIBRARY}"
+    : # We're only using the full path to the archive, which is output in static_libs
 }

 function mason_clean {

[springmeyer]

@kkaefer current thoughts on this? It looks like this was never changed: we still provide output for both static_libs and ldflags for boost (and probably a lot of other packages). This is harmless as long as the client prefers the static_libs output, correct?

[kkaefer]

In most packages, we manually return an empty string for ldflags. In some cases, e.g. GLFW, we're manually removing the library link flag, while retaining link flags for third party/system libraries.