Adding add sample log to Elwin

Refs #7711
Started the implementation of Rwp cost function.  Refs #7476.
Checkpointing work.  Refs #7476.
Checkpointing work.  Refs #7476.

Implemented the Hessian matrix and Derivative vector.  It works with
non-Levenberg-Marquadt minimzers.  The result looks fine.
Modifed to be inherited.  Refs #7476.

Modify CostFuncLeastSquare such that CostFuncRwp can inherit from it.
Changed inheritance.  Refs #7476.

Made CostFuncRwp inherit from CostFuncLeastSquares other than
CostFuncFitting.
Refactored Instrument actor visitors to make them more generic.

Re #5403
Added unit test on using NeutronBk2BkExp.  Refs #7880.
refs #7957. Add log scaling feature.
Revert "refs #7957. Add log scaling feature."

This reverts commit 0d49ebb5d33de98321b4e79bc53193a0b9d7bd17.
Revert "Revert "refs #7957. Add log scaling feature.""

This reverts commit a588b297a0d001ef12bcd74703003f7ec9c083ad.
Refactor ComptonScattering to allow for a background.

The constraint matrices need to expand if a background is to be
included.
Refs #7492
Allow ComptonScatteringCountRate to include a background.

Refs #7492
Refs #5422 Added UI and py routines for Indirect Foreign.
Refs #5422 Added base classes for Indirect Foreign.
Refs #5422 Added concrete tabs for Indirect Foreign.
Refs #5422 Updated GUI files extensions.
Refs #5422 Adding and updating IPFs for Indirect Foreign.
Refs #5422 Correcting Syntax.
Refs #5422 Re-added ILL instruments to Mantid.