RFR(S): 8237589: Fix copyright header formatting

[Mikael Vidstedt]

Please review this change which fixes the copyright headers for 300+ files. The vast majority of the changes are related to the formatting of the year ranges, but there are a few other types of fixes in there in an attempt to keep you awake while reviewing this.

jbs: https://bugs.openjdk.java.net/browse/JDK-8237589
webrev: https://cr.openjdk.java.net/~mikael/webrevs/8237589/webrev.00/open/webrev/

Cheers,
Mikael