scons build systems

scons build systems
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Allows static libs to be passed correctly to the linker (i.e., full paths to
libs which end in ".a" are passed to linker without processing).  I've been
using this on linux release builds since sometime around 2.49 without problem
but hesitated to commit since I don't know if it would affect any other
platforms.  If you're using static libs on another platform and it breaks,
let me know.