Change default drag and drop text for controls
Merge pull request #73 from gbaty/fix_control_drop_in_shell

Change default drag and drop text for controls
Add :checkbox: role to sphinx (Display a checkable checkbox, usefull for check lists)
Merge pull request #74 from gbaty/sphinx_role

Add :checkbox: role to sphinx
Improve ProjectPreview display and add libraries and startups to the list
Merge pull request #75 from gbaty/improve_project_preview

Improve project preview
New service to get a unique interpreter ipython.
Fix some bugs in tests.
move lpy dependencies into plantlab
restore picklable curves remove by mistake
lpy model has a default input
fix error with name inside prepare_inputs
remove unused part in test
Move loader and saver (plantgl dependent AND unused) in legacy.
Fix setup.py s.
Move lpy controls into plantlab.
Project: add items method to return all items for a category
Add meta information for project categories
Use dynamic approach to display project summary
Save project after metadata changes
Follow flake8
Add path as locals for reading the configuration

Old config was setting the dir path using path.py module.
We need it to be backward compatible.
First draft for plugin manager
All applet plugin follow standard plugin convention: __call__ return applet class.
To add widget in mainwindow and fill menus, just call "graft(mainwindow)" method.