Workspace Algebra & other Python enchancements

[Nick Draper]

This should cover the following related items:

• Enabling Workspace overloads to perform +,-,*,/
• Automatically extracting output workspaces to global variables in python
  • Including refreshing these before each run of scripts from within Mantidplot
  • Dead workspace variables need to die gracefully
• SimplePythonAPI algorithms need to accept workspace variables as input and output workspaces
  • This might be done by overloading the action of the str() Fn
• Make it easier to print the workspace list in python

[Martyn Gigg]

(In [3366]) Added workspace operator overloads to Python API. The wrappers have also been split out into separate files, one for each namespace, so that there is a bit more structure. Re #947

[Martyn Gigg]

(In [3367]) I forgot a few other changes that I had made for the workspace algebra stuff. Re #947

[Martyn Gigg]

(In [3368]) Fix the ADS test. Re #947

[Martyn Gigg]

(In [3382]) Added a Framework class written in Python, which inherits from the C++ one, to be the main interaction point from Python so that we can keep track of dead workspaces and set their variables to None. Re #947

[Martyn Gigg]

(In [3385]) Fix for broken test compilation. Re #947

[Martyn Gigg]

(In [3387]) Fix to installer script. Re #947

[Martyn Gigg]

(In [3394]) Added notifications for replacing a workspace to the PyFrameworkManager. Also added protection for threaded enviroments calling Python code. Re #947

[Martyn Gigg]

(In [3396]) Added methods for more easily accessing workspaces from algorithms. Re #947

[Martyn Gigg]

(In [3400]) Switched off Python framework observers until I've sorted the threading issues properly. Re #947

[Martyn Gigg]

(In [3402]) Reimplemented the Python notification listeners. The Python Framework now has to be told whether to try and acquire the global interpreter lock. This should aboid the deadlock issue in MantidPlot. Re #947

[Martyn Gigg]

(In [3405]) Added a simple list method to the Python framework for printing the workspace list more easily. Also improved access on the WorkspaceProxy for groups, you can ask it if it is group and it is also indexable. Re #947

[Russell Taylor]

Worked for me.

[Russell Taylor]

Actually, right after this I discovered a few issue:

• No history is produced when running these (right click and "Show History on the output workspace does nothing).
• Put a single value as the first argument of one of the non-commuting binary operations and they get swapped around. I.e. ask for 2/a and you get a/2, ask for 1-a and you get a-1.
• In fact, it turns out that the algorithms themselves won't let you do this. They report that "The sizes of the two workspaces are not compatible".

[Martyn Gigg]

(In [3501]) Fixes for workspace algebra operators in reverse order. Re #947

[Stuart Campbell]

This ticket has been transferred to github issue ​1795