The span selector edges can no longer be reversed.
Update CHANGES.txt for 0.7 release.
Merge pull request #262 from francisco-dlp/update_changes

Update CHANGES.txt for 0.7 release.
Add docstring for the public subpackages.
Automatic style corrections courtesy of autopep8.
Merge pull request #263 from francisco-dlp/document_public_modules

Document public modules
Add DielectricFunction to set_signal_type docstring.
Merge pull request #264 from francisco-dlp/add_df_to_signal_type

Add DielectricFunction to set_signal_type docstring.
RENAME: Signal.apply_function -> map
Automatic style corrections courtesy of autopep8.
Add notes section to map docstring to explain the differences with the Python function.
Merge pull request #265 from francisco-dlp/RENAME_apply_function_map

Rename apply function map
Rename Hyperspy -> HyperSpy.
Merge pull request #266 from francisco-dlp/Rename_Hyperspy

Rename Hyperspy -> HyperSpy.
Rename hyperspectral -> multidimensional.
Automatic style corrections courtesy of autopep8.
DOC: what's new for EDS
Merge pull request #267 from pburdet/DOC_EDS_new_0.7

DOC: what's new for EDS
Revert ModifiableSpanSelector edge crossing
Merge pull request #268 from francisco-dlp/RENAME_hyperspectral

Rename hyperspectral