Modified Developer Start Guide VIM instructions

fix slowdown introduced by gh-4865

Plugins will not load without calling `vundle#end()`

Finally, the 'bug' wasn't a bug as the optimization didn't applied in the case that would cause problems.

Fix batchnorm error in buildbot.

Use pip3 to install for python3 on ubuntu 14.04

Fix abstractconv_grad dilation and enable border_mode tests

add ddof to var and std, apply Fred-fix to opt

Ignore more frequently the mrg rng state in the old back-end. 

Grad assert

scan/scan_op: Convert known_grads to OrderedDict

This fixes a typo in bbc749ab, which would give problems with
non-symmetric filter dilations for border_modes full or half. (This
error was only visible in the debug mode.)

This commit also fixes the test, which previously would not actually
test different border_modes, but would always use the same default.

Finally, this commit adds border_mode = "half" to the tests.

jenkins test print commands

More fixes for Jenkins

Pre cleanup

Remove useless reshape

Add device in the compiledir_format

Fix #4809

This was probably causing a different order of operation
during gradient computation in scan for each run. With this
fix I'm able to finally reproduce results on my RNN system.

Fix issue #4809

Handle filter_dilation in the abstractconv_grad* perform methods

Fix jenkins

We have to make the distinction between Op types in the original and
optimized graph

That way it can work with @parameterized and GPU

The tolerances are just a starting point, we may need to adjust them
later.