Remove flags that aren't used anywhere

doc/install.txt

@@ -815,21 +815,6 @@ try the following.
       [gcc]
       cxxflags = -L/opt/local/lib
 
-- An obscure ``Bus error`` can sometimes be caused when linking
-  Theano-generated object files against the ``framework`` library in Leopard.
-  For this reason, we have disabled linking with ``-framework Python``, since on
-  most configurations this solves the ``Bus error`` problem. If this default
-  configuration causes problems with your Python/Theano installation and you think
-  that linking with ``-framework Python`` might help, then either set
-  the :envvar:`THEANO_FLAGS` environment variable with
-  ``THEANO_FLAGS=cmodule.mac_framework_link`` or edit your ``~/.theanorc`` to
-  contain
-
-    .. code-block:: cfg
-
-      [cmodule]
-      mac_framework_link=True
-
 - More generally, to investigate libraries issues, you can use the ``otool -L``
   command on ``.so`` files found under your ``~/.theano`` directory. This will
   list shared libraries dependencies, and may help identify incompatibilities.

doc/library/config.txt

@@ -940,13 +940,6 @@ import theano and print the config variable, as in:
     code that can't be cached because there is no c_code_cache_version()
     function associated to at least one of those Ops.
 
-.. attribute:: config.cmodule.mac_framework_link
-
-    Bool value, default: False
-
-    If set to True, breaks certain MacOS installations with the infamous
-    Bus Error.
-
 .. attribute:: config.cmodule.remove_gxx_opt
 
     Bool value, default: False

theano/configdefaults.py

@@ -571,10 +571,6 @@ AddConfigVar(
     IntParam(8),
     in_c_key=False)
 
-AddConfigVar('experimental.mrg',
-             "Another random number generator that work on the gpu",
-             BoolParam(False))
-
 AddConfigVar('experimental.unpickle_gpu_on_cpu',
              "Allow unpickling of pickled CudaNdarrays as numpy.ndarrays."
              "This is useful, if you want to open a CudaNdarray without "
@@ -1084,12 +1080,6 @@ AddConfigVar('gcc.cxxflags',
              # Added elsewhere in the c key only when needed.
              in_c_key=False)
 
-AddConfigVar(
-    'cmodule.mac_framework_link',
-    "If set to True, breaks certain MacOS installations with the infamous "
-    "Bus Error",
-    BoolParam(False))
-
 AddConfigVar('cmodule.warn_no_version',
              "If True, will print a warning when compiling one or more Op "
              "with C code that can't be cached because there is no "