SickConfig.hh should be included by the implementations but not the header files. They are necessary when compiling the library but are not necessary for linking against the library.
The problem with including them in the header files is that the #defines are global and can conflict with other defines. The ones I had trouble with in particular were PACKAGE and PACKAGE_NAME for they conflicted with another misconfigured autotools package.
My work around was to delete the contents of SickConfig.hh from the installed version. The SickConfig.hh file should probably not even be installed.