Dual toolchain (revised pull request)

[gtristan]

Updated dual-toolchain branch with a fix to gcc-gplv3.sh

We configure gcc with --disable-lto but gcc still produces the binutils wrapper tools gcc-nm, gcc-ar and gcc-ranlib, which require the presence of the lto plugin.

Now we just forcefully remove these wrappers after the build so that unsuspecting packages dont attempt to use these in place of regular binutils for linking and get link time errors.