Change the location of the logo so that it does not overlap with anything and replace it with a less pixelated version

Move the negative sign to the constant to avoid having to take the negative of an entire array. Also use a multiplication rather than a division (even though a division by 2 is a special case).

Adding an option to change the output file format. The available formats depends of the host, but usually png, pdf, ps, eps and svg is supported.

Example:
--format svg

Use the --series <series1 series2...> option to indicate one o more of this series:
stellar_attenuated,
stellar_unattenuated,
nebular,
dust,
agn,
radio,
model.

If the --seriesdisabled flag is used, then all available series will be enabled, except the ones that are indicated in the --series option. If not, then only the series indicated in the --series option will be enabled.

SED: Adding --xrange and --yrange to set the plot axis ranges (optionally). The format are [<min>]:[<max>], where min and max are Python floats (e.g. 1E4).

Examples:
--xrange :1E3  # automatically X min
--yrange 1E2:1E4

Correct the scaling of the best-fit to account to the difference between the grid and the observed redshifts/distances.

Take into account the effect of the differential redshifting between the observed and grid redshifts.

* Include dependence of pcigale.analysis_modules.utils.Counter class, to perform the progress message.
* Fixed error in the way to pass "outdir" parameter to the pool in chi2, and pdf.

Because this, this Class can be used in a more generic ways.

Currently, a standard installation of CIGALE (`pip install .`) results
in an unusable installation as `setuptools.find_packages` does not find
PEP-420 packages.

This commit adds `pcigale/managers/__init__.py` to correct this.
Alternatively, we may want to switch
`setuptools.find_namespace_packages`.

# Conflicts:
#	pcigale_plots/__init__.py

Now it is possible to choose the folder that contains the output files (the "out" folder). It is expected that the default configuration file pcigale.ini be sibling of the "out" folder.

BEST_RESULTS and MOCK_RESULTS now are available in the command line options (optional)

Minor optimization in logo reading in workers.
Fix logo position.
Adding logging.