Removed erroneous line in licence throughout code.

This MR removes the line License for the specific language governing rights and limitations under which has been erroneously included in the header of every file.

Fixes #161 (closed).

changed milestone to %v5.0.0

added Proposed patch label

assigned to @dmoxey

@dmoxey I used a script to fix this, so please could you check each and every change to make sure there are no mistakes?

merged

mentioned in commit 02b6159e