message: Allow to use hunspell installed into system using pkg-config.
diff: +pkg_check_modules(HUNSPELL hunspell)
  +
  +if(HUNSPELL_FOUND)
  + add_library(hunspell INTERFACE)
  + #target_compile_definitions(hunspell PUBLIC HUNSPELL_STATIC)
  + target_include_directories(hunspell INTERFACE ${HUNSPELL_INCLUDE_DIRS})
  + target_link_libraries(hunspell INTERFACE ${HUNSPELL_LINK_LIBRARIES})
  +else()
  set(HUNSPELL_DIR ${CMAKE_CURRENT_SOURCE_DIR}/hunspell)
  add_library(hunspell
  @@ -26,3 +34,4 @@ target_include_directories(hunspell
  set_target_properties(hunspell PROPERTIES
  AUTOMOC ON
  )
  +endif()
  