Change license to Apache License 2.0

Change the license from LGPL 2.1 to AL 2.0. This includes the following tasks:

• Identify all contributors who have code in master (to be 3.4)
• Remove contributors who are Red Hat employees (work-for-hire)
• Remove contributors who were Red Hat employees at the time of the contribution
• Contact the remaining contributors and ask for their permission to change the license
• Change the web site to list both LGPL 2.1 (<= 3.3) and AL 2.0 (>= 3.4) licenses
• Change LICENSE in master: include both licenses, state that code <= 3.3 is licensed under LGPL 2.1 and later code is licensed under AL 2.0