[12,8u] RFR: JDK-8212158: FX: Update copyright year in docs, readme files to 2019

[Kevin Rushforth]

Hi Murali,

Please review the following to update the copyright year for the API 
docs to 2019:

JBS: https://bugs.openjdk.java.net/browse/JDK-8212158
12 webrev: http://cr.openjdk.java.net/~kcr/8212158/webrev/
8u webrev: http://cr.openjdk.java.net/~kcr/8212158/8u/webrev/

I'm sending the 8u backport for review at the same time to expedite 
getting this into the 8u-dev repo ahead of the RDP2 freeze for 8u202.

-- Kevin