Cleanup build logs related to documentation

Currently some errors and warnings are appearing in the console when running the script which is producing the new website and documentation.
These should be solved, as at least some of them seem to be reporting real problems (e.g. missing image files).
Also it will be nice that we take out warnings, or debug messages, in case they are not relevant (so that when changes are done which are producing problems, we can easily spot these).
Meanwhile, in the old tvb_documentation:

/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/monitors.py:docstring of tvb.simulator.monitors.numpy_add_at:11: SEVERE: Unexpected section title.

Parameters
----------
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/monitors.py:docstring of tvb.simulator.monitors.numpy_add_at:23: SEVERE: Unexpected section title.

Examples
--------
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/monitors.py:docstring of tvb.simulator.monitors.numpy_add_at:33: WARNING: Literal block expected; none found.
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/monitors.py:docstring of tvb.simulator.monitors.numpy_add_at:42: WARNING: Literal block expected; none found.
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/simulator.py:docstring of tvb.simulator.simulator.numpy_add_at:11: SEVERE: Unexpected section title.

Parameters
----------
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/simulator.py:docstring of tvb.simulator.simulator.numpy_add_at:23: SEVERE: Unexpected section title.

Examples
--------
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/simulator.py:docstring of tvb.simulator.simulator.numpy_add_at:33: WARNING: Literal block expected; none found.
/WORK/Hudson/workspace/TVB - MacOS x64/scientific_library/tvb/simulator/simulator.py:docstring of tvb.simulator.simulator.numpy_add_at:42: WARNING: Literal block expected; none found.