Top imports

[felix-hilden]

Let's provide top level imports already before we get to version 2.

Some things to do:

• Change the documentation to use the new imports
• Add a notice of the upcoming change
• If possible, establish a proper deprecation

[felix-hilden]

I think properly deprecating (warning users) is not possible to do consistently. We would need to change where everything is defined, and then import them back to the original locations. Then top level imports would be done from the new places and if the original locations are imported, a warning would be issued. But we still need to provide a way to set options. So I think a notice will be enough. Along with changing all the documentation, users will likely naturally gravitate towards the new style of imports.

[felix-hilden]

And just to have the links: this also addresses issues #81 and #154 by adding the top imports. Neither is closed, because work is left to be done.