Add model.get_component. Finding a component by name in a model

Useful when Hyperspy is called a library, since the components are
not directly callable.
ENH: suppress all the remaining plot_intensity_map
Style corrections.
DOC: parameters
DOC: describibg sample
DOC: EDS plot
DOC: gte lines intensity
ENH: correct .rpl Brucker
Add . Also improve the Scree plot section of the User Guide by incluiding a figure.
Merge pull request #176 from pburdet/ENH_load_brucker_rpl

ENH: correct .rpl Brucker
Merge pull request #177 from francisco-dlp/ENH_get_explained_variation

Enh get explained variation
Add missing figure from previous commit
Merge branch 'master' of https://github.com/hyperspy/hyperspy
Merge branch 'master' into DOC_improved_EDS
Rename get_component -> __getitem__ .
Merge pull request #2 from francisco-dlp/model_get_specific_component

Rename get_component -> __getitem__ .
Automatic style corrections, courtesy of autopep8
Change component.name to property: check for duplicate when namechange

If the component is a part of a model, and the name of the model is
changed, the component will check if there are any components with
the same name.
Merge pull request #181 from francisco-dlp/autopep8

Automatic style corrections, courtesy of autopep8
Change model.append behavior: checks for duplicate component names

If a component with the same name already exists, the name will be
add _0, _1, _2, ...
If the component has no name, it will get the same name as its
_id_name: "Gaussian", "Voigt",...