Merged from trunk: By default, when 32 bit x86 build is requested, i686 instruction set is chosen now. i386 instruction set removed since de facto it is not supported by some core libraries (Boost.Atomic and Boost.SmartPtr) and major operating systems. The minimum 32 bit x86 instruction set is i486 now. Also added a few more instruction sets that appeared in recent CPUs.

[SVN r84254]

libs/spirit

@@ -1 +1 @@
-Subproject commit 0f3fe1e6cd31466b9b93b1f1a1c9ec249876d93a
+Subproject commit 14f4b73ef77b36c880b342722b7485849957885f

tools/build

@@ -1 +1 @@
-Subproject commit 0b0a10b7538d5ff39b735fd46fac2e5e509cddf2
+Subproject commit 378009d006707a46be60248cd7865eb7018cb4b9