RFR: [small,docs] JDK-8240971 Fix CSS styles in some doc comments

[Jonathan Gibbons]

Please review a simple fix regarding the non-standard use of some CSS in 
some doc comments.

 From the JBS Description:

Recently, for the display of javadoc block tags, javadoc changed from 
using an inconsistent set of CSS class names on the generated 'dt' 
elements to using a single new name ("notes") on the enclosing 'dl' 
element.

There are a few (4) places in the main JDK code where the old-style 
names were used explicitly in doc comments, in order to emulate the 
appearance of a list of block tags. These use-sites should be fixed up. 
They are in the following files:

open/src/java.base/share/classes/module-info.java
open/src/java.se/share/classes/module-info.java
open/src/java.management.rmi/share/classes/module-info.java
open/src/jdk.jconsole/share/classes/module-info.java

In addition, these four files used the style attribute to force the font 
to be used. The font is now set in the standard CSS for "notes", and so 
the local use of a "style" attribute is no longer necessary.

-- Jon

JBS: https://bugs.openjdk.java.net/browse/JDK-8240971
Webrev: http://cr.openjdk.java.net/~jjg/8240971/webrev.00/index.html
API: http://cr.openjdk.java.net/~jjg/8240971/api.00/index.html