Revert ATLAS package

[jdemeyer]

There are some problems with generic binaries (SAGE_FAT_BINARY=yes) in the new ATLAS spkg. In order not to delay the release of Sage 5.10 any longer, I will revert #10508.

On cicero (Fedora 16 i686), the build fails: ​http://build.sagemath.org/sage/builders/Skynet%20cicero%20%28Fedora%2016%20i686%29%20bin/builds/90/steps/shell_5/logs/atlas

Note the use of -DATL_3DNow and lots of "Illegal instruction" messages, proving that this likely is not a generic binary, unlike what it should be.

On arando (Ubuntu 13.04 i686), the build works but there is doctest failure:

sage -t devel/sage/sage/matrix/matrix_double_dense.pyx
**********************************************************************
File "devel/sage/sage/matrix/matrix_double_dense.pyx", line 3823, in sage.matrix.matrix_double_dense.Matrix_double_dense.is_positive_definite
Failed example:
    H.is_positive_definite()
Expected:
    True
Got:
    False
**********************************************************************