omnitrace find_package support (#3)

* omnitrace find_package support

- Fix to INSTALL_DESTINATION for configure_package_config_file
- Fixes to ConfigInstall.cmake and omnitrace-config.cmake.in

* Test find_package

cmake/ConfigInstall.cmake

@@ -0,0 +1,38 @@
+# include guard
+include_guard(GLOBAL)
+
+include(CMakePackageConfigHelpers)
+
+install(
+    EXPORT omnitrace-library-targets
+    FILE omnitrace-library-targets.cmake
+    NAMESPACE omnitrace::
+    DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/cmake/omnitrace)
+
+# ------------------------------------------------------------------------------#
+# install tree
+#
+set(PROJECT_INSTALL_DIR ${CMAKE_INSTALL_PREFIX})
+set(INCLUDE_INSTALL_DIR ${CMAKE_INSTALL_INCLUDEDIR})
+set(LIB_INSTALL_DIR ${CMAKE_INSTALL_LIBDIR})
+set(PROJECT_BUILD_TARGETS user dl)
+
+configure_package_config_file(
+    ${PROJECT_SOURCE_DIR}/cmake/Templates/${PROJECT_NAME}-config.cmake.in
+    ${PROJECT_BINARY_DIR}/install-tree/${PROJECT_NAME}-config.cmake
+    INSTALL_DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/cmake/omnitrace
+    INSTALL_PREFIX ${CMAKE_INSTALL_PREFIX}
+    PATH_VARS PROJECT_INSTALL_DIR INCLUDE_INSTALL_DIR LIB_INSTALL_DIR)
+
+write_basic_package_version_file(
+    ${PROJECT_BINARY_DIR}/install-tree/${PROJECT_NAME}-version.cmake
+    VERSION ${PROJECT_VERSION}
+    COMPATIBILITY SameMajorVersion)
+
+install(
+    FILES ${PROJECT_BINARY_DIR}/install-tree/${PROJECT_NAME}-config.cmake
+          ${PROJECT_BINARY_DIR}/install-tree/${PROJECT_NAME}-version.cmake
+    DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/cmake/${PROJECT_NAME}
+    OPTIONAL)
+
+export(PACKAGE ${PROJECT_NAME})