We were stuck on the 4.5.0 tag from develop, since we searched for the
latest tag, but release tags are done on the master branch.
This commit rips out all the code for deriving the version on git tags.
Instead, we define major, minor, and patch versions in the CMakeLists
and then pass it on to:
- the `libosrm.pc` `pkg-config` file
- a `version.hpp` header that makes use of the preprocessor's string
concatenation to provide an easy way for generating version string
literals such as "v4.8.0".
That is, in the source code please now use the following defines:
#define OSRM_VERSION_MAJOR "@OSRM_VERSION_MAJOR@"
#define OSRM_VERSION_MINOR "@OSRM_VERSION_MINOR@"
#define OSRM_VERSION_PATCH "@OSRM_VERSION_PATCH@"
#define OSRM_VERSION "v" OSRM_VERSION_MAJOR "." OSRM_VERSION_MINOR "." OSRM_VERSION_PATCH
