build: detect new erlang version format correctly

- OTP 17.0 uses a different numbering system for releases and patches, but not semver.org
- the major version number will be bumped for the first time in 4 years
Fix comparison warning on ./configure
Fix setting autoconf flags for using nifs
docs: update supported Erlang/OTP and SpiderMonkey versions

- matches what the code can support after last Mochiweb update
- update .travis.yml file to match 17.0 release
- update docs
Move Erlang 17 support to 1.6.0 release
COUCHDB-2233 - Correct HTML interpolation instances in documents.

Further updating instances of <%= and to <%- within documents to correctly handle HTML interpolation.

Tested for regression in
- 34.0.1847.131
- Safari 7.0.2

Signed-off-by: Alexander Shorin <kxepal@apache.org>