Move json encoding out of riak_object

Revisiting https://github.com/basho/riak_kv/pull/88
But using riak_object_json encode/decode and leaving old methods in
riak_object.erl with a deprecation warning.
Addressing review comments

Using constants for links and last modified headers.
Removing old @spec.
String detection should not allow 256 int values.
Make the memory backend config behave as documented

Also, fix yessir backend, which has the same potential issue.
Don't return the timestamp information when folding objects

The memory backend, with TTL enabled, stores the values as {Timestamp,
Value}, and it was leaking that information during fold_objects, which
would cause handoff to fail.
Merge pull request #606 from basho/adt-memory-config

Make the memory backend config behave as documented
Merge pull request #607 from basho/adt-memory-ttl-folds

Don't return the timestamp information when folding objects
fix riak_kv_backend standard tests

The riak_kv_backend standard tests, which are invoked by riak backend
tests, were not actually testing anything. The standard_test/2 function was
coded as an eunit test generator but it was returning functions that
themselves were returning lists of test generators. Unfortunately eunit
won't work through that many levels of test generator indirection so the
tests weren't actually running.

Change the standard tests to use regular assertMatch rather than the test
generator form _assertMatch so that the tests actually run. Due to
bitcask's use of the process dictionary, add the local test directive to
the top test spec to execute the tests in the same process where the
backend initialization function runs. Fix one of the fold_keys tests to
expect the correct result. Change all the delete/3 calls to delete/4 calls,
as that's what backends now implement. Modify the memory backend test setup
to ensure its ets tables are created appropriately for testing.
Fix gh611 - do not set the start_term to the last seen key for eq

The clause for equals query pagination was missing.
Fix counter protobuf message codes
Merge pull request #613 from titanous/patch-1

Fix counter protobuf message codes
Add millisecond timemout parameter to API 2i endpoints

Accepts non_neg_integer milliseconds (zero for inifinty)
Add support for an app.config setting for 2i timeouts
Strip index term from result before passing to MR

MR expects only a Key, 2i ranges now return {index_term, key}
Merge pull request #616 from basho/gh610-2i-timeout

Add millisecond timemout parameter to API 2i endpoints
Merge pull request #618 from basho/gh617-2i-mr

Strip index term from result before passing to MR
Use 1.4.1 deps
Roll version 1.4.1
Use riak_pipe 1.4.1
git rm .travis.yml
Nice catch, Sean: remove TravisCI image from README.org
Merge branch 'slf-disable-travisCI'