update to 2.1.0 and simplify cmake calls by using according macros OBS-URL: https://build.opensuse.org/request/show/259759 OBS-URL: https://build.opensuse.org/package/show/devel:libraries:c_c++/libyajl?expand=0&rev=25
OBS-URL: https://build.opensuse.org/request/show/67238 OBS-URL: https://build.opensuse.org/package/show/devel:libraries:c_c++/libyajl?expand=0&rev=7