Update riak_index parse_float to correctly handle scientific notation.
Add eunit tests.
Add riak_index_backend behavior, update riak_index_mi_backend to use the
behavior, swap argument order to stay consistent with riak_kv_backend.
Add index backend unit tests.

AZ458
Validate delete options pertaining to the get and put seperately
Reshuffle the REST error handler clauses, and add a missing one
Merge pull request #111 from basho/az419-update-delete-interface

Az419 update delete interface
keydata support

inputs to a map phase are now allowed to be {Bucket, Key}, {{Bucket,
Key}, KeyData}, [Bucket, Key], or [Bucket, Key, KeyData], as with the
legacy system
pass link tag as keydata
correct chashfun for link kv_get fitting
switch on riak_kv app-env 'mapred_system' in riak_kv_wm_mapred

use pipe emulation if set to 'pipe', or legacy system if set to 'legacy'
add pipe/legacy mapred system switch to link walker

required correcting some list-stitching behavior in reduce phases,
because link_walker uniques links with a reduce phase before mapping to
get their values.  reduce phases now send their outputs one element at a
time, instead of the whole list at once
change link fitting output to [B,K,Tag] format for JSON-ouput compatibility

if a query is submitted to the /mapred resource, and it contains a link
phase with keep=true, then the output link format must be json-ifiable,
i.e. the [B,K,Tag] format

this was not possible before the previous patch, fixing the grouping of
phase output
legacy/pipe switch support in protobuf server
Implement 2I querying via list_keys.

AZ459
Add merge_index dependency.
Change field type matching to use lists:suffix/N rather than regular expressions.

AZ458
Merge branch 'rtk-dev1' into rtk-dev1-AZ459

Conflicts:
	src/riak_index.erl
Fix compiler warnings.
Merge pull request #112 from rklophaus/rtk-dev1

2I: Implement RiakKV Index Backend (AZ458)
Remove unused defines, avoid double-call of FinalFun.

AZ459
Fix normalizing new delete parameters over PB interface

Fixes az419