- Removed cmake-modules dependencies

- Added a tarball source-tree warning on compile

cmake/GetPastisGitRevision.cmake

 # --------------- get git revision info ---------------
 
-list(APPEND CMAKE_MODULE_PATH "${PASTIS_SOURCE_DIR}/cmake/cmake-modules")
-include(GetGitRevisionDescription)
-
 set(HAS_PASTIS_GIT_INFO "TRUE")
 
 find_package(Git QUIET)
@@ -50,12 +47,19 @@ endif()
 
 string(FIND "${PASTIS_GIT_TAG}" "${CMAKE_PASTIS_VERSION}" FOUND_VERSION_SUBSTR)
 
+if(FOUND_PASTIS_GIT_INFO EQUAL 0)
   if("${FOUND_VERSION_SUBSTR}" STREQUAL "-1")
     message("")
     message ("######  CMake code version  ${CMAKE_PASTIS_VERSION} and")
     message ("######  git revision info  ${PASTIS_GIT_TAG} do not match!")
     message("")
   endif()
+else()
+  message("")
+  message ("######  This source tree is not a git repository!")
+  message ("######  If you intend to change sources consider to clone a git repository!")
+  message("")
+endif()
 
 # Generates revision header file candidate
 configure_file("${PASTIS_SOURCE_DIR}/utils/pastis_git_revision.hpp.in"