Resolve "Query version of libaec"

Closes #4 (closed)

include/libaec.h.in

@@ -38,6 +38,11 @@
 #ifndef LIBAEC_H
 #define LIBAEC_H 1
 
+#define AEC_VERSION_MAJOR @PROJECT_VERSION_MAJOR@
+#define AEC_VERSION_MINOR @PROJECT_VERSION_MINOR@
+#define AEC_VERSION_PATCH @PROJECT_VERSION_PATCH@
+#define AEC_VERSION_STR "@PROJECT_VERSION_MAJOR@.@PROJECT_VERSION_MINOR@.@PROJECT_VERSION_PATCH@"
+
 #include <stddef.h>
 
 #ifdef __cplusplus