title: Change `base_compiledir` to save compiled files in another directory
body: <p><code>theano.base_compiledir</code> refers to the directory where the compiled files are stored.</p>
  <p>Is there a way where I could permanently set <code>theano.base_compiledir</code> to a different location, perhaps by modifying the content of some internal Theano files ?</p>
  <p><a href="http://deeplearning.net/software/theano/library/config.html" rel="nofollow noreferrer">http://deeplearning.net/software/theano/library/config.html</a> does explain ways for configuring <code>theano</code> in some aspect but I still couldn't address my question.</p>
  <p>I am using Ubuntu.</p>