explicitly add STATIC keyword to iris_lib target

This fixes a bug where CMake tries to link the Iris binary
to the shared lib version of iris_lib (which doesn't exist).
Linking exe against static lib to avoid shared library dependencies when installing locally - still building and installing shared library for other launchers
Updating readme with blog address
Merging pull request from Andre and now linking exe against static lib
Building in support for both boost filesystem v2 and v3 - permits the use of boost versions < 1.46 (as currently available on E100 naster image)