add OS information to JESVersion message

This is designed to make it easier on us when people copy/paste the
version information. (We already include their Java, so why not?)
rewrite bug reporter dialog

It does the same thing now, but it has a JTextPane with more
information and guidance. It also displays the version information
directly so the user can just copy-paste it into the bug report.
add version to About dialog as header

I figured this was a pretty reasonable thing to want in the About
dialog.