Add CPPCHECK find

  - CPPCHECK_EXECUTABLE stores the cppcheck executable path
    - look for cppcheck executable in PATH env. var. or CPPCHECK_DIR/bin or CPPCHECK_BINDIR (env. var. or CMake variables)
  - CPPCHECK_VERSION stores the version

modules/find/FindCPPCHECK.cmake

+###
+#
+# @copyright (c) 2017 Inria. All rights reserved.
+#
+###
+#
+# - Find CPPCHECK bin directory
+# Use this module by invoking find_package with the form:
+#  find_package(CPPCHECK
+#               [REQUIRED]) # Fail with error if cppcheck is not found
+#
+# This module finds headers and cppcheck library.
+# Results are reported in variables:
+#  CPPCHECK_FOUND           - True if cppcheck executable is found
+#  CPPCHECK_EXECUTABLE      - cppcheck executable directory found
+#
+# The user can give specific paths where to find the libraries adding cmake
+# options at configure (ex: cmake path/to/project -DCPPCHECK_DIR=path/to/cppcheck):
+#  CPPCHECK_DIR             - Where to find the base directory of cppcheck
+#  CPPCHECK_BINDIR          - Where to find the executable cppcheck
+# The module can also look for the following environment variables if paths
+# are not given as cmake variable: CPPCHECK_DIR, CPPCHECK_BINDIR
+
+if (NOT CPPCHECK_FOUND)
+  set(CPPCHECK_DIR "" CACHE PATH "Installation directory of CPPCHECK library")
+  mark_as_advanced(CPPCHECK_DIR)
+  if (NOT CPPCHECK_FIND_QUIETLY)
+    message(STATUS "A cache variable, namely CPPCHECK_DIR, has been set to specify the install directory of CPPCHECK")
+  endif()
+endif()
+
+set(ENV_CPPCHECK_DIR "$ENV{CPPCHECK_DIR}")
+set(ENV_CPPCHECK_BINDIR "$ENV{CPPCHECK_BINDIR}")
+set(CPPCHECK_GIVEN_BY_USER "FALSE")
+if ( CPPCHECK_DIR OR CPPCHECK_BINDIR OR ENV_CPPCHECK_DIR OR ENV_CPPCHECK_BINDIR )
+  set(CPPCHECK_GIVEN_BY_USER "TRUE")
+endif()
+
+
+if (NOT CPPCHECK_FIND_QUIETLY)
+  message(STATUS "Looking for CPPCHECK")
+endif()
+
+# Looking for executable
+# ----------------------
+
+# Add system include paths to search include
+# ------------------------------------------
+unset(where_to_look)
+if(CPPCHECK_BINDIR)
+  list(APPEND where_to_look "${CPPCHECK_BINDIR}")
+elseif(CPPCHECK_DIR)
+  list(APPEND where_to_look "${CPPCHECK_DIR}")
+elseif(ENV_CPPCHECK_BINDIR)
+  list(APPEND where_to_look "${ENV_CPPCHECK_BINDIR}")
+elseif(ENV_CPPCHECK_DIR)
+  list(APPEND where_to_look "${ENV_CPPCHECK_DIR}/bin")
+else()
+  string(REPLACE ":" ";" _path_env "$ENV{PATH}")
+  list(APPEND where_to_look "${_path_env}")
+endif()
+list(APPEND where_to_look "${CMAKE_PLATFORM_IMPLICIT_INCLUDE_DIRECTORIES}")
+list(APPEND where_to_look "${CMAKE_C_IMPLICIT_INCLUDE_DIRECTORIES}")
+list(REMOVE_DUPLICATES where_to_look)
+
+find_program(CPPCHECK_EXECUTABLE
+  NAMES cppcheck
+  HINTS ${where_to_look}
+)
+mark_as_advanced(CPPCHECK_EXECUTABLE)
+
+if(CPPCHECK_EXECUTABLE)
+  execute_process(COMMAND ${CPPCHECK_EXECUTABLE} "--version" OUTPUT_VARIABLE CPPCHECK_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
+  string(REGEX REPLACE "Cppcheck " "" CPPCHECK_VERSION "${CPPCHECK_VERSION}")
+endif()
+
+# check that CPPCHECK has been found
+# ----------------------------------
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(CPPCHECK DEFAULT_MSG
+                                  CPPCHECK_EXECUTABLE
+                                  CPPCHECK_VERSION)