Merge #103: cmake: Fix package configuration file

c373a94 cmake: Fix package configuration file (Hennadii Stepanov)

Pull request description:

  When loading a package configuration file, `find_package` defines variables to provide information about the call arguments. In particular, `CMAKE_FIND_PACKAGE_NAME` represents the package name.

  This PR uses this variable instead of a hardcoded name, making the use case suggested in #98 (comment) workable:
  ```cmake
  find_package(Libmultiprocess COMPONENTS Lib)
  find_package(LibmultiprocessNative COMPONENTS Bin
    NAMES Libmultiprocess
  )
  ```

ACKs for top commit:
  ryanofsky:
    Code review ACK c373a94

Tree-SHA512: 493cfd62c4992c9753772844c0a96004d45eb1c807986b7ce7871fdf0debede79d9f9fbe22ecce0a92d4d0b5a2d24f0067c2b5816f5210a8f5bcbb41d04fb917

Author: ryanofsky

cmake/Config.cmake.in

@@ -7,24 +7,24 @@
 set(_Libmultiprocess_supported_components Bin Lib)
 
 # If no components specified, include all components.
-list(LENGTH Libmultiprocess_FIND_COMPONENTS Libmultiprocess_FIND_COMPONENTS_len)
-if(Libmultiprocess_FIND_COMPONENTS_len EQUAL 0)
-    set(Libmultiprocess_FIND_COMPONENTS ${_Libmultiprocess_supported_components})
+list(LENGTH ${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS ${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS_len)
+if(${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS_len EQUAL 0)
+  set(${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS ${_Libmultiprocess_supported_components})
 endif()
 
-if ("Bin" IN_LIST Libmultiprocess_FIND_COMPONENTS)
+if ("Bin" IN_LIST ${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS)
   include("${CMAKE_CURRENT_LIST_DIR}/TargetCapnpSources.cmake")
 endif()
 
-if ("Lib" IN_LIST Libmultiprocess_FIND_COMPONENTS)
+if ("Lib" IN_LIST ${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS)
   include(CMakeFindDependencyMacro)
   find_dependency(CapnProto)
 endif()
 
-foreach(_comp ${Libmultiprocess_FIND_COMPONENTS})
+foreach(_comp ${${CMAKE_FIND_PACKAGE_NAME}_FIND_COMPONENTS})
   if (NOT _comp IN_LIST _Libmultiprocess_supported_components)
-    set(Libmultiprocess_FOUND False)
-    set(Libmultiprocess_NOT_FOUND_MESSAGE "Unsupported component: ${_comp}")
+    set(${CMAKE_FIND_PACKAGE_NAME}_FOUND False)
+    set(${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE "Unsupported component: ${_comp}")
   endif()
   include("${CMAKE_CURRENT_LIST_DIR}/${_comp}Targets.cmake")
 endforeach()