Update reference/constraints/Callback.rst

addViolationAtSubPath() is deprecated since version 2.2 and will be removed in 2.3. Use addViolationAt() instead.
[DI] PrependExtensionInterface sync doc with latest Sf2 changes
sf2.2 note: _method override disabled by default
Link method to docs as per @WouterJ suggestion
Merge pull request #2164 from sstok/patch-3

Update reference/constraints/Callback.rst (dont use deprecated method)
[#2164] Removing one more reference to deprecated addViolationAtSubPath
Merge pull request #2181 from vicb/dic/prepext

[DI] PrependExtensionInterface sync doc with latest Sf2 changes
Merge pull request #2189 from inanimatt/patch-1

sf2.2 note: _method override disabled by default