Start clearing up annotation syntax for functions.

[HansOlsson]

It is intended to work towards close #3495 - but it doesn't handle all of the annotations as some are problematic.

Note that I deliberately added default values in some cases, I believe they are the correct ones.

It might be that we should add more, or view this as enough to close it - and later think about the rest.

The problem with the other ones are:

• "Trivial": the external function ones can specify either an array or a scalar.
• "Messy": The derivative and inline-annotations don't fit into the pattern for two reasons:
  • The "value" is not a value - so no good type for the declaration (it is a function for derivatives, and something else for inverse)
  • The optional sub-modifiers for values, like smoothOrder(normallyConstant=x)=2

(I have might have missed some that could be handled.)

[eshmoylova]

I updated the description to make it a link to the issue #3495 for an easy lookup.

[henrikt-ma]

Suggesting minor change that will make this more compatible with #3621.

[henrikt-ma]

I'm afraid defaults should be presented in the text rather than as a default binding.

[HansOlsson]

Language group: Describe these in text (not as default), and then later revisit all.

[HansOlsson]

Language group: Describe these in text (not as default), and then later revisit all.

This has now been implemented. @henrikt-ma

[henrikt-ma]

Basically good, but there was at least one need for improved language.

[henrikt-ma]

I think this would fit even better before the three rules about identical meaning of annotation combinations.

[henrikt-ma]

Only a trivial reordering of paragraphs remaining.