update mailmap
SI-7322 Interpolator idents must be encoded

Otherwise, they are not found.

This matters for term names with a differential encoding.

Footnote, normally ident() encodes, but INTERPOLATIONID
is !isIdent, so that is not used here.  Maybe that would
be the better improvement.
Avoid generic collections operations hot paths

 - Use a specialized version of List#{map, collectFirst}
   These special case mapping over an empty list and avoid
   allocating.
 - Avoid nonEmpty in favor of `ne Nil`

I see in the order of 2% speedup.

Perhaps more useful is that
these methods no longer dominate the YourKit profiles, even though
profiler bias due to safepoints at allocation of the ListBuffer
might have been overstating their significance.
SI-7124 make macro definitions prettier in scaladoc

Macros are now prettier in scaladoc, by
 - hiding the `macroImpl` annotation
 - showing the `macro` modifier in front
Merge pull request #3444 from retronym/topic/opt6

Avoid generic collections operations hot paths
Merge pull request #3441 from gourlaysama/t7124

SI-7124 make macro definitions prettier in scaladoc
Merge pull request #3422 from adriaanm/mailmap

update mailmap
Merge pull request #3424 from som-snytt/issue/7322

SI-7322 Interpolator idents must be encoded