Mercurial 5.3.2 released

[Augie Fackler]

Regular bug fix release, notes should get posted "soon."

Also as a note: we're planning that the 5.4 release will be shepherded by Pulkit (cc'ed) rather than me, so be prepared for the release signer to change starting with 5.4rc0 or thereabouts.

(Release notes lag because I'm trying to not do everything for releases, to reduce how much of hg has me as a single point of failure.)