refs #8557 Two questions to 2 suspicious places of code

Two places found after code review which look like wrong. Questions to code were placed after //!!! mark
Merge branch 'master' into feature/8557_SNSvsISIS
Refs #8723 add LoadIsawSpectrum algorithm
Refs #8723 add LoadIsawSpectrum algorithm
Refs #8816 add predict peaks to SCD interface
Refs #8816 move predictPeaks after UB
Refs #8816 add argument
Refs #8816 make params visible
Refs #8838 Prevent deletion of loaded workspaces.

This is consistent with the other routines in IDA.
Refs #8838 Disable option on plot when not available.
Refs #8816 fix dspacing params input
Refs #8816 longer interface and enable parameters by default
Fixed vector sizes in autocorrelation method

Since vector size will not change, the correct size is allocated
directly at construction.
Creating vectors with data for good wire only in PoldiAutoCorrelation5
Added POLDI chopper representation

It follows the same principle as the detector representation, providing
an interface that can be implemented in different ways if the chopper
should ever change.
Some small comment corrections in POLDI classes
Changed exception handling in PoldiBasicChopper to conform with
PoldiHeliumDetector
Refs #8281 Tidy up the S(Q,w) interface on C2E.
Refs #8281 Hook up data selector widget to interface.
Refs #8281 Fix tab order for binning input on S(Q,w) interface.