Improve the handling of child algorithms in Python Algorithms

[Nick Draper]

Make any pythonsimpleAPI call inside a python algorithms a child algorithms by default.

steps:

1. add a global switch to pythonsimpleAPI to make any subsequent algorithms to be child algs
2. set and reset that switch either side of PyExec
3. Add documentation of how to override the switch in case you really want to

[Mathieu Doucet]

Note that turning this feature ON by default may break existing python algorithms. When an algorithm is executed as a sub-algorithm, the output workspace is not added to the ADS. The user has to get it from the executed sub-alg if it is needed after execution.

The following (very common) code would not work:

def PyExec(self):
  input_ws = self.getProperty("InputWorkspace")
  SomeAlgorithm(InputWorkspace=input_ws, OutputWorkspace="tmp_out")
  SomeOtherAlg(InputWorkspace="tmp_out", OutputWorkspace="result")

Tmp_out can't be transferred to the next algorithm in this way with sub-algorithms.

[Nick Draper]

Bulk move of tickets at the end of iteration 28

[Nick Draper]

"New" tickets moved at the code freeze of iteration 29

[Nick Draper]

Bulk move of tickets to iteration 31 at the iteration 30 code freeze

[Nick Draper]

Moved to iteration 33 at iteration 32 code freeze

[Janik Zikovsky]

Refs #2636, #4752: make python algo's child algorithms set as children

Changeset: 2685a3810c9032b3a82319362f73d6d9c47bbe2c

[Janik Zikovsky]

Refs #2636, #4752: method for children of python algorithms

Changeset: cb95b77c2142d57d65ce2834ac31a481ce5cc9f4

[Janik Zikovsky]

Refs #2636, #4752: enabling use of the method for

python algorithm child algos

Changeset: 377a143c163aabdedf25c8cd16da428751b33220

[Janik Zikovsky]

To work around this problem, I am trying a method to specify that you want the workspaces to be stored in the ADS, and specifying python algorithm's children as children also.

This should fix the incorrect history that these workspaces had, while keeping the existing python algos working.

[Janik Zikovsky]

OK this is an OK though temporary fix. See #4770 for follow-up work.

Message to testers of the future: by the time you test this, the method will likely be gone. See #4770 also.

[Janik Zikovsky]

Refs #2636: log algorithm info for Python child algorithms.

Also re-enable workspace locking which I accidentally left disabled

Changeset: a52d7ef6a4aa7a578f9dad50031390c215889a5e

[Peter Peterson]

This ticket is being closed as #5158 covers problems that eventually came up.

[Stuart Campbell]

This ticket has been transferred to github issue ​3483