Ditz issue update
Apparently 'xml' is a better idea than 'rdfxml'
Merge branch 'fix-spdx-rdflib-error'
Add a duktape.org logo draft
Relocate touch-icon to a subdirectory
Update buildsite for new touch-icon location
Add EPS version of Duktape logo
Merge branch 'add-duktapeorg-logo'

Add a placeholder Duktape logo (used for AllSeen Alliance).
Add alt setjmp/longjmp providers, OSX auto _setjmp
Document setjmp/longjmp alt feature options
Makefile: commented out setjmp provider opts
Add doc/guide section for perf sensitive envs
Release note: alternative setjmp providers
Merge branch 'alternative-setjmp-calls'

- Add feature options to force an alternate long control transfer
  (setjmp/longjmp) provider

- Default to _setjmp/_longjmp on OSX: setjmp/longjmp will save signal
  mask on OSX and are significantly slower than _setjmp/_longjmp
  (GH-55)

- Add an internal placeholder document for performance options, and
  mention sejtmp providers there

- Update guide with a bit more expanded sections on feature options
  for specific environments
Ditz issue update
Ditz issue update
More guide description of experimental features
Merge branch 'guide-experimental-note'
Ditz issue update