refs #2552 - mantidplot ida interface, allow users to fix fitting parameters on "convfit" tab using a context menu

Corrections to some example scripts that had become a little out of date. Also some minor fixes for functionality that had broken. Fixes #861

refs #2552 - mantidplot ida interface, allow users to fix fitting parameters on "furyfit" tab. partially complete.

Refs #2016: MDEventWorkspace factory to create MDEventWorkspaces of a given number of dimensions. New algorithm for creating an empty MDEventWorkspace.

re #2466. MDWorkspace implements getPoint and getCell methods implied by IMDWorkspace. Optimizations will be made later.

Refs #2379 Calculate ISAW TOF for peaks and find in TOF grid; Use TOF grid for integration with IkedaCarpenterPV

re#1839 - The problem was commands like Ctrl+C on script interpreter is routed to global editing command handlers in Application window.
Added code to handle Ctrl+C on script widget in the application window copySelection() method.

Application window copySelection() handles copy actions on all windows of type MDISubWindow in Mantidplot and 
if any of these windows is kept opened and a Ctrl+C on script interpreter widget the command was getting routed to application window code.
Fixed this.However when I do paste command (Ctrl+V shortcut ) on script  interpreter it gives an error -conflicting
Ctrl+V shortcut Need to fix this.

Better fix for path searching. Will fix the failing SANS tests that my simple fix for sav files broke yesterday. Re #1811

Fixes a possible crash with the AlgorithmHistory window when a dialog is cancelled. Also cleared a warning. Fixes #2551