yahns 1.15.0

Minor changes to reduce allocations and simplify our code
and dependencies.  Nothing particularly interesting unless
you're the type of person who appreciates brake pedals
in with holes drilled in them for weight reduction.

11 changes since 1.14.1 (2016-12-14):
      stream_input: avoid allocation for common #read case
      proxy_pass: add a note about the instability of this
      tee_input: simplify conditional for writing to temporary file
      proxy_http_response: reduce memory pressure from larger headers
      http_response: make response headers eligible for GC, sooner
      update more referenced URLs to be HTTPS
      chunk_body: nodoc this internal class
      Revert "use olddoc 1.1.0 for generating NEWS + NEWS.atom.xml"
      gemspec: stop advertising "private" email address
      doc: design_notes: we do not use EPOLLEXCLUSIVE
      README: update with disclaimer about subscription

Ovt punatrf pbzvat...