simplify AC:ViewPaths::_prefixes. by making it recursively traversing up the inheritance chain, classes can override local prefixes.
deprecate AbC:Base::parent_prefixes.
rename ::_local_prefixes to ::local_prefixes to state the public attribute.
document the latter.
make ::local_prefixes private, test overriding it and remove documentation for overriding ::_parent_prefixes.
Use i18n master to run tests
Merge remote-tracking branch 'apotonick/simplify-prefixes'

This is the rebased version of #15026

Closes #15026
Improve CHANGELOG entry
._prefix is private API so we should not recommend to override it
Mark _prefix as nodoc

These methods are private API.
Follow the documentation guideline
Refactoring the code to make consitional return explicit
Following documentation guideline
We need an explicit return

If we don't return early Ruby will memoize the value of the prefix of
the parent class what will make the subsequent searchs to not work as
expected.

If the early return we are avoiding the memoization.

But when using the deprecated path we need to memoize the value, so we
are not using early return for the deprecated path.
Update Redcarpet to 3.1.2

This version fixes an API breakage between 3.0 and 3.1 ; the header
method's arity should not have changed.

[ci skip]
[ci skip]add updated information, ref[#522c0fd]
Merge pull request #15096 from robin850/patch-20

Update Redcarpet to 3.1.2
Merge pull request #15108 from arthurnn/i18n_master

Use i18n master to run tests
Merge pull request #15074 from kuldeepaggarwal/docs-changes

Add missing information, ref[#522c0fd]
remove warning `ambiguous first argument; put parentheses or even spaces`
Merge pull request #15110 from kuldeepaggarwal/fix-warning

remove warning `ambiguous first argument; put parentheses or even spaces`