RFR: JDK-8185867: fix a11y and html issues in jdk.jdi docs

[Jonathan Gibbons]

Please review this fix for some of the docs for the jdk.jdi module.

Most of the changes are relatively straightforward. The biggest change 
was to the introductory tables in the Type and Value classes. These were 
both conceptually "many tables in one", with embedded headers within the 
tables. These tables have been split into separate tables.  Of the four 
tables, 3 could reasonably have been changed to the commonly used 
"striped" style class, but the use of rowspan in the second table on the 
Type page makes "striped" a less than ideal choice for that one. So, for 
local consistency, all tables have been left with styling similar to before.

BEFORE: http://download.java.net/java/jdk9/docs/api/com/sun/jdi/Type.html
AFTER: http://cr.openjdk.java.net/~jjg/8185867/api.00/com/sun/jdi/Type.html

BEFORE: http://download.java.net/java/jdk9/docs/api/com/sun/jdi/Value.html
AFTER: http://cr.openjdk.java.net/~jjg/8185867/api.00/com/sun/jdi/Value.html

As always, the changes are just to the accessibility and visual 
presentation; no semantic changes to the specification are intended.

JBS: https://bugs.openjdk.java.net/browse/JDK-8185867
Webrev: http://cr.openjdk.java.net/~jjg/8185867/webrev.00
New API: http://cr.openjdk.java.net/~jjg/8185867/api.00

-- Jon