Add a force-load dependency feature to allow for cases where the linker removes 'unused' symbols as is common in the linking model of Apple's Objective C

[SVN r61684]

tools/build

@@ -1 +1 @@
-Subproject commit 656169f5f39e4e429faf666d303017d05a42303d
+Subproject commit 99a99424d80f0b1d64145d115be029e0cf5c2ff0