GDA-5479 Add test program to reproduce Jython server problems by interrupting threads

* Strip stuff out of GDAJythonInterpreter to allow it to be used in a test
  program
Merge remote-tracking branch 'origin/project/GDA-5479' into 8.34
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-core.git into 8.34
GDA (8.34) Default ORBClass and ORBSingletonClass to the only classes we use.

Also make the default event channel name local.eventChannel and tidy up
the test cases.

This allows the gda.ORBClass, gda.ORBSingletonClass and gda.eventChannelName
properties to be removed from java.properties.
CORE: add script to load preferred version of Java
Revert "CORE: add script to load preferred version of Java"

This reverts commit b59497e293906c1817a35bde2ac0a5661738e5fe.

This script should be in dls-config instead.
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-core.git into 8.34
NOJIRA (8.34) Disable reduced gui check when baton management is off

It is no longer possible to be lumbered with a reduced gui even when the
baton management system is off (its default state). The property checked
is: 'gda.accesscontrol.useBatonControl'.
Revert "Merge remote-tracking branch 'origin/project/GDA-5479' into 8.34"

This reverts commit 5134e7a2cf15e520322d36dbe35861c3d3c031e5, reversing
changes made to 6d4b3e16fbfedc8cff4df5a5e0c13c6235d248e4.
Merge remote-tracking branch 'origin/gda-5479' into 8.34
GDA-5479 (8.34) loq whether new Writer or old OutputStream is in use
RotationViewer: allow "Move to zero" button to appear independently of the fixed step buttons

Until now, setting showResetToZero to true when constructing a RotationViewer
only caused the "Move to zero" button to appear if fixed step buttons were also
turned on (by calling configureFixedStepButtons).
Add handy command-line program for listing objects in the RMI registry
RotationViewer: allow access to top-level Composite after createControls has been called
CORE (8.34) Noted that TwodDataSetProcessor is extended by Eric's FlippingDevice from i06 and/or i07
Core - Fix bug in determination of event channel name registered by
eventserver
MTGDA (8.34) Add .hooks/post-checkout to correct core/bin/gda execute perms.

Note that this will only be copied into .git/hooks on deployment and
will only be run on a command line git checkout.

Checking out or switching branches from egit may still leave files
without group and other execute permissions.
Merge remote-tracking branch 'origin/8.34' into 8.34
DiCAT: throw more useful exception if username/password properties aren't set
Replace hard coded project external paths with gda_root variable based paths.

This should allow jython unit tests to run without project specific project
external paths being set.

To set up the gda_root variable (needed only once per workspace):

  Window > Preferences > Pydev > Interpreter - Jython >
    String Substitution Variables tab > Add variable
      Key:   gda_root
      Value: /dls_sw/iXX/software/gda_versions/gda_X.YY/

Project paths based on gda_root assume that a standard deployment is in
use, with the workspace and a workspace_git subdirectory immediately
under the specified gda_root directory.