Update Containerfiles, start CLI tool.

+ Containerfiles: default to using g++.  Most of the dev machines aren't
  working with clang yet; until this is sorted out, they'll need to use
  g++.
+ Add script to determine if the git-tree is tagged.
+ Add basic CMake skeleton and start CLI tool.

cmake/install.cmake

@@ -0,0 +1,27 @@
+### Install ###
+
+include(CMakePackageConfigHelpers)
+
+### library packaging for CMake and pkgconfig to find built targets.
+write_basic_package_version_file(
+	${PROJECT_NAME}Config.cmake
+	VERSION ${PACKAGE_VERSION}
+	COMPATIBILITY SameMajorVersion
+)
+write_basic_package_version_file(
+	${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+	VERSION ${PROJECT_VERSION}
+	COMPATIBILITY SameMajorVersion)
+configure_file(${PROJECT_NAME}.pc.in ${PROJECT_NAME}.pc @ONLY)
+
+### set up installation targets.
+
+install(TARGETS ${PROJECT_NAME} LIBRARY DESTINATION lib)
+install(FILES ${HEADERS} DESTINATION include/${PROJECT_NAME})
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc
+	DESTINATION lib/pkgconfig)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
+	      ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
+	DESTINATION share/${PROJECT_CMAKE_CONFIG_NAME}/cmake)
+
+