tbdiff now an autotools project, installs shared library

Hi folks, I've just converted tbdiff into an autotools project. It also builds and installs a shared library (libtbdiff-1.so) and a pkg-config file (tbdiff-1.pc) now. The two tools tbdiff-create and tbdiff-deploy simply link against that. This has various benefits and is easier to work with for people who want to build and use tbdiff. For the details of this rather big change, please see https://gitorious.org/baserock/tbdiff/commit/c7a4f00fd701c7e1bd071c7a5aa8... - Jannis