BLD: Improve finding Armadillo by the installed library (#132)

* improve finding armadillo

* fix condition

* Fix if/else/endif style

* remove checks, fix interface target

* revert some inconsistent if style

cmake/carmaDependencyTargets.cmake

@@ -25,18 +25,24 @@ IF (NOT DEFINED PYTHON_EXECUTABLE)
 ENDIF ()
 
 # Armadillo dependency
-IF (NOT TARGET armadillo)
+IF (NOT TARGET armadillo AND NOT TARGET armadillo::armadillo)
     IF (carma_FIND_REQUIRED)
         FIND_PACKAGE(Armadillo REQUIRED)
     ELSE ()
         FIND_PACKAGE(Armadillo)
     ENDIF ()
-    ADD_LIBRARY(armadillo INTERFACE)
-    TARGET_INCLUDE_DIRECTORIES(armadillo INTERFACE ${ARMADILLO_INCLUDE_DIRS})
-    TARGET_LINK_LIBRARIES(armadillo INTERFACE ${ARMADILLO_LIBRARIES})
 ENDIF ()
-IF (armadillo_FOUND OR ARMADILLO_FOUND OR TARGET armadillo)
-    ADD_LIBRARY(armadillo::armadillo ALIAS armadillo)
+IF (NOT TARGET armadillo::armadillo)
+    IF (TARGET armadillo)
+        ADD_LIBRARY(armadillo::armadillo ALIAS armadillo)
+    ELSEIF (Armadillo_FOUND)
+        ADD_LIBRARY(armadillo INTERFACE)
+        TARGET_INCLUDE_DIRECTORIES(armadillo INTERFACE ${ARMADILLO_INCLUDE_DIRS})
+        TARGET_LINK_LIBRARIES(armadillo INTERFACE ${ARMADILLO_LIBRARIES})
+        ADD_LIBRARY(armadillo::armadillo ALIAS armadillo)
+    ENDIF ()
+ENDIF ()
+IF (TARGET armadillo::armadillo)
     LIST(APPEND carma_INCLUDE_DIRS ${ARMADILLO_INCLUDE_DIRS})
 ENDIF ()