HEADS-UP: [8u60] New WebKit + compiler upgrade for FX 8u60

[Kevin Rushforth]

As a heads-up we are ready to push the updated WebKit [1] for JEP-239 
[2] plus the needed compiler upgrade changes to 8u-dev tomorrow. This is 
similar to what we did for FX 9 about 5 weeks ago [3].

Here is a short summary of the changes:

* The updated WebKit will be pushed into 8u-dev (for 8u60) tomorrow 
morning, Thursday, Mar 26, around 8:00 am Pacific. It would be very 
helpful if other committers refrained from pushing non-trivial changes 
tomorrow morning (Pacific time).

* As was the case for FX 9, this means that our production builds will 
switch to the new compilers: VS2013 on Windows; Xcode 5.1.1 on Mac; gcc 
4.8 on Linux. FX 8u-dev will still be buildable on the old compilers as 
long as you don't build WebKit (it is disabled by default).

* As a reminder, this is the last week that changes pushed to 8u-dev 
will be automatically synced into 9-dev. I will send out an e-mail 
tomorrow outlining the new procedures.

[1] https://javafx-jira.kenai.com/browse/RT-40055
[2] http://openjdk.java.net/jeps/239
[3] 
http://mail.openjdk.java.net/pipermail/openjfx-dev/2015-February/016700.html

-- Kevin