Moved the atlasexternals submodule into a subdirectory.

To have a bit better organisation in the repo once I introduce a
ROOT package specific for this repository.

.gitmodules

-[submodule "atlasexternals"]
-	path = atlasexternals
+[submodule "Externals/atlasexternals"]
+	path = Externals/atlasexternals
 	url = ../../atlas/atlasexternals.git

CMakeLists.txt

@@ -5,9 +5,10 @@ cmake_minimum_required( VERSION 3.6 )
 project( AtlasStats VERSION 0.0.1 LANGUAGES C CXX )
 
 # Set where to pick up AtlasCMake and AtlasLCG from.
-set( AtlasCMake_DIR "${CMAKE_SOURCE_DIR}/atlasexternals/Build/AtlasCMake"
+set( AtlasCMake_DIR
+   "${CMAKE_SOURCE_DIR}/Externals/atlasexternals/Build/AtlasCMake"
    CACHE PATH "Location of AtlasCMake" )
-set( LCG_DIR "${CMAKE_SOURCE_DIR}/atlasexternals/Build/AtlasLCG"
+set( LCG_DIR "${CMAKE_SOURCE_DIR}/Externals/atlasexternals/Build/AtlasLCG"
    CACHE PATH "Location of AtlasLCG" )
 mark_as_advanced( AtlasCMake_DIR LCG_DIR )
 

package_filters.txt

@@ -4,16 +4,16 @@
 #
 
 # Select which packages to pick up from atlasexternals.
-+ atlasexternals/External/Davix
-+ atlasexternals/External/dcap
-+ atlasexternals/External/LibXml2
-+ atlasexternals/External/Python
-+ atlasexternals/External/PyAnalysis
-+ atlasexternals/External/ROOT
-+ atlasexternals/External/TBB
-+ atlasexternals/External/XRootD
++ Externals/atlasexternals/External/Davix
++ Externals/atlasexternals/External/dcap
++ Externals/atlasexternals/External/LibXml2
++ Externals/atlasexternals/External/Python
++ Externals/atlasexternals/External/PyAnalysis
++ Externals/atlasexternals/External/ROOT
++ Externals/atlasexternals/External/TBB
++ Externals/atlasexternals/External/XRootD
 
 # Do not pick up anything else from atlasexternals.
-- atlasexternals.*
+- Externals/atlasexternals.*
 
 # Everything else (packages held in this repository) is fair game...