[isabelle-dev] Java 7 update 6

[Makarius]

Oracle has released the important Java 7u6 yesterday, see also 
http://www.oracle.com/us/corporate/press/1735645

It means much more uniformity of the 3 plaform families: Linux, Mac OS X, 
Windows. For example, Mac OS X users now get the IsabelleTextBold font by 
default without modifying the local system.  It also means that Chinese 
glyphs are *unavailable* in a uniform manner, because Apple's unofficial 
glyph substitution for the JVM is no longer used.

I generally expect thing to become better, since problems show up more 
uniformly and can be addressed more easily.

Isabelle/b19ba23e70c5 already uses jdk-7u6 together with 
jedit_build-20120813.  This is a mandatory update of components, although 
just plain Isabelle/Scala (e.g. isabelle build) still happens to work with 
JDK 1.6 if that happens to be used by a side-entry.


 	Makarius