RFR: 8221260: Initialize more class members on construction, remove some unused ones

[Leo Korinth]

Hi,

This is a code cleanup. This change removes some warnings when opening 
the files from within Eclipse.

I try to:
  - Initialize more class members as soon as possible
  - Remove some (5) unused members, and one unused faulty constructor
  - Prefer to use initializer list instead of constructor body

Enhancement:
https://bugs.openjdk.java.net/browse/JDK-8221260

Webrev:
http://cr.openjdk.java.net/~lkorinth/8221260/00

Testing:
Mach5 tier1-3

Thanks,
Leo