Clang fixes

On Mavericks using clang/clang++ and Mountain Lion using gcc/g++ or clang/clang++ this successfully builds all tests for csharp,  java, go, php, perl, python, ruby, and tcl.  Also ran tests for D - fixed clang issues, other errors I observed were same for this branch and master.

To build using clang I ran configure like
     ./configure.sh --prefix=/some/dir 'CC=clang' 'CXX=clang++' 'CXXFLAGS=-stdlib=libc++'

I also had to first build a local version of mono, since need a 64 bit version of mono to run the csharp tests.
I used mono 3.2.3, configured like
     ./configure.sh --prefix=/some/dir --with-glib=embedded --enable-nls=no --host=x86_64-apple-darwin10
I also had to fix-up references to ./install-sh in Makefiles to make the paths absolute, for some reason.