RFR 8059631: Use of '#' to represent MethodHandle kind is confusing

[Jonathan Gibbons]

Trivial review to "tweak" the presentation of method handles in javap's 
presentation of the constant pool.

1.  A misleading initial '#' is removed.
2.  The description of the kind of MethHandle is changed to use the name 
given in the JVMS.

JBS: https://bugs.openjdk.java.net/browse/JDK-8059631
Webrev: http://cr.openjdk.java.net/~jjg/8059631/webrev

-- Jon