Fixed documentation about default value of Theano's compilation directory.

doc/install.txt

@@ -89,7 +89,9 @@ automatic code generation, but that way is much, much slower.
 
 - `THEANO_COMPILEDIR`:
     A directory with read/write access permissions where theano will store
-    autogenerated code and C modules. Default: ``$HOME/.theano``. If this
+    autogenerated code and C modules. Default:
+    ``$HOME/.theano/compiledir_xxx`` where ``xxx`` is a platform identifier.
+    If this
     directory does not exist or does not have the correct permissions,
     theano will try to create it with the correct permissions. If that fails,
     an exception will be raised and no C code will be compiled.

doc/internal/lisa_labo.txt

@@ -26,13 +26,6 @@ Use something like the following in your .bashrc:
     # use up to two threads in the MKL routines
     OMP_NUM_THREADS=2
 
-    # IMPORTANT!
-    # Use the local-temporary directory as a cache.
-    # If several jobs start simultaneously and use a common
-    # cache, then the cache may be corrupted.
-    # Theano is not process-safe or thread-safe in this sense.
-    THEANO_COMPILEDIR=/ltmp/<username>_theano
-
 You may also need to run the following from your shell: 
 
 .. code-block:: bash