Update early access site for JBDS 8 changes

This page still needs some improvements:
https://devstudio.jboss.com/updates/8.0-development/

Namely the column on the left.

1. If not already installed, download and install Oracle JDK or OpenJDK 7 (or 6).

This is not true for JBDS 8. Probably should be just 7 for now?

3. To start the installer, double-click the installer file or open a command line and enter /path/to/java jar jbdevstudio*.jar

We should change this to jboss-devstudio-*.jar

Then we link to the script. Please check if it's still relevant.

And finally this: Supported OS + JVM Combinations

• apparently this needs to be updated. As the Beta2 blog says [1] we now use HTML Preview for HTML5 which should work on most platforms. I'm not completely sure about this, it needs to be checked.
  Also, there is now no 32-bit java on the mac anyway.

Oh and I almost forgot: At the bottom of the page, there is this:
Note: If you install JBoss Developer Studio updates into an existing Eclipse 4.3 (Kepler) installation...

• needs to be updated to say "Eclipse 4.4 (Luna)"

[1] http://tools.jboss.org/blog/2014-06-19-beta2-for-luna.html