ISSUE-18: sync with latest couchdb changes & latest private rcouch release.
edit readme.
fix build

- rebar sources were missing due to a bad pattern in the .gitignore file
- point rebar to github
speed tests on travis
fix R15B03 target
add missing couch_rel src.
add couch_randomdoc to the build.

Add the couch_randomdoc application to retrieve randomly a doc from a
database or a view.
fix build. couch_httpd.hrl doesn't exist anymore

For now the #httpd{} record is still in the couch application waiting
for RCOUCH-15 so use a special branch to make sure we can build this
release.
fix 140-* test

apache couchdb has README.rst where we have README.md.
remove spurious print
fix test/etap/140-attachment-comp.t

rmeove spurious print, prove wasn't able to catch the output...
RCOUCH-20: add geocouch support

RCOUCH-20 done