Updated the Athena and AthenaP1 projects to use the latest version of

the atlasexternals repository. To get GCC checker warnings again, and to
store the exact version of the repository used for the build, in the
ReleaseData files generated for the projects.

Projects/Athena/externals.txt

@@ -5,5 +5,5 @@
 # an "origin/" prefix before it. For tags however this is explicitly
 # forbidden.
 
-AthenaExternalsVersion = 1.0.4
+AthenaExternalsVersion = 1.0.5
 GaudiVersion = v27r1.012

Projects/AthenaP1/externals.txt

@@ -5,5 +5,5 @@
 # an "origin/" prefix before it. For tags however this is explicitly
 # forbidden.
 
-AthenaExternalsVersion = 1.0.4
+AthenaExternalsVersion = 1.0.5
 GaudiVersion = v27r1.012