Bump license year; simplify README and avoid duplication.

Preparing to release 6.1.

Preparing to release cx_Oracle 6.0.3.

Preparing to release 6.0.2.

Preparing to release 6.0.1.

Documentation tweaks.

Improve installation documentation.

Preparing to release cx_Oracle 6 rc 1.

Preparing to release cx_Oracle 6.0b2.

Update documentation to indicate that Oracle 12.2 is now supported an…

…d exactly

which versions of Python are supported.