BLVII (8.34) Fix Epics time series code to read current data.

It used to read out the data from the previous scan!
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-epics.git into 8.34
EPICS (8.34) Create AreaDetector Merlin driver that triggers a an energy
threshold sweep at each point in scan.
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-epics.git into 8.34
GDA (8.34) Fix EpicsTrajectoryMoveController to work with multinput scannables with an offset onjust one input
Merge branch '8.34' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-epics.git into 8.34
MXGDA-1599 Set isBusy flag in PVScannable.asynchronousMoveTo *before* doing the caput

Otherwise there's a risk (observed on I02) of the put callback coming back to
GDA, and isBusy being set to false, *before* isBusy is set to true. This causes
the scannable to get 'stuck' in the busy state and waitWhileBusy hangs forever.
BLVI (8.34) Add null terminator to byte array passed to caput.

Fix problem where junk was being left at the end of the file path.
Merge remote-tracking branch 'i06-1/8.34' into 8.34
Add bin to pydev project path and a gda_root based external path for jca.

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.
Move jca from being an external library in pydevproject to internal.
Merge remote branch 'origin/8.34' into 8.36