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
DOC: parameters
DOC: describibg sample
DOC: EDS plot
DOC: gte lines intensity
Fixes #175 , plotting line spectra was raising an exception.
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__ .
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.
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",...
Merge branch 'master' into DOC_improved_EDS

Conflicts:
	hyperspy/_signals/eds.py
	hyperspy/tests/signal/test_eds_tem.py
Change model.__getitiem__ behavior: check if components have same name

__getitem__ will now raise an error it finds several components with
the same name
Add docs for calling components in a model
Merge branch 'master' into model_get_specific_component
Add tests for calling and naming components in a model
Merge branch 'master' into model_get_specific_component_cleanup

Conflicts:
	hyperspy/component.py
	hyperspy/model.py
Fix docstring in model.__getitem__
Fix typo in model.__getitem__ docstring