Move ISIS indirect reduction into Mantid and write proper system tests for it

[abuts]

Mantid currently uses DirectInelastic reduction algorithms which is used for converting data to energy transfer. The integrity of these is verified by the system tests.

These algorithms are the basis for customized reduction, actually used in ISIS excitation group to process the experimental results.

The custom algorithms mainly rely on Mantid algorithm but override different settings from different places and have some parts of the algorithm implemented differently.

1. The custom algorithm are not covered by system tests and can be easily broken by the changes in Mantid core

2. Two (actually three) sets of default parameters plus possibility to set up parameters from the script itself make it difficult to understand what parameter is actually used.

The purpose of this ticket is to bring all ISIS inelastic reduction script into Mantid and verify its integrity by proper system tests.

Isis reduction script should be very thin layer over verified Mantid reduction scripts.

[abuts]

This issue was originally trac ticket 6667