update AEIThorns::Trigger doc, correct parameter steerabiblity, fix skipping non-set triggers

[Roland Haas]

the attached patches do:

• reduce_int.patch: allow reductions on non-integer variables
• int_param.patch: allow non-real parameters to be checked
• doc_scalars.patch: update documentation to mention handling of grid scalars
• no-checkpoint-scalars.patch: don't checkpoint temporary variables
• ignore_empty_triggers.patch: fix code so that empty paramater/variable names cause it to skip a trigger which is what param.ccl documents it to do
• fix_parameter_steerability.patch: some parameters are parsed into a GH extension at STARTUP and thus cannot be (meaningfully) steered afterwards. This patch marks those parameters as STEERABLE=RECOVER.

Keyword: Trigger

[Frank Löffler]

The patches look fine. I am not sure about why empty triggers would be desirable, but I also cannot see why they would hurt. The overhead should not matter. The 'series' file was probably uploaded by accident. Please commit within the next two days, or wait until after the release.

[Roland Haas]

I cannot commit to AEIThorns/Triggger it seems (forbidden). Frank: since you are the author, you would seem to be the person to authorize for me to be added to it. In theory someone should answer emails send to [e-mail] and I will ask to be added. The series file was actually intentional in case you used quilt and wanted to apply the patches in the correct order. I suggest to not commit it though :-).

[Frank Löffler]

[e-mail] would be the right point of contact. I do not have power over the AEI repositories. Since you use the thorn so much I think it would be good to get you write permissions. I certainly approve of it.

[Frank Löffler]

Request is sent. Let's cross fingers.

[Roland Haas]

Applied as rev 38 to 46 of Trigger.