Create an input which generates a datalist tag

Create an input which supports http://www.w3schools.com/tags/tag_datalist.asp
Used as follows
f.input :fieldname, as: datalist, collection: ["list", "of", "items"]
collection option accepts all formats supported by rails' options_for_select
Add documentation for datalist input

Add an example in README
Fix scope of DatalistInput class
Add documentation for DatalistInput class
Minor fix for file_input documentation
Add tests for datalist input

Add tests for both kinds of collections that can be provided
Add more generic helpers in custom_macros, which can be better reused
Add datalist input to autoload list
Remove invalid TODO
Improve intent of the regex used to strip out _id, and other PR fixes
update appriasal tasks setup and link to github repositories for rails edge
add rails 4.1 to testing
Merge pull request #1064 from twalpole/travis_failures

Update CI set-up for Rails 4.1 and unreleased Rails edge gems.
fix wrong version of Rails in 4.1 appraisal ref #1064
we might as well deprecate Rails 4.0 with 5 on the way
Deprecate Rails < 4.1
gem updates and mock additions needed to get the tests to pass on edge rails
Merge pull request #1071 from twalpole/rails_edge_errors

gem updates and mock additions needed to get tests running on edge rails
Only write generic form inoput to output_buffer when needed.
This keeps it clean for other tests to ensure no false positives.
add failing test for 1 == '0' comparison
fix bug by ensuring we're comparing Integers
Merge pull request #1073 from justinfrench/1072-boolean-integer-bug

Fix boolean integer bug
add Rails 4.2.0.beta1 to build for master
cherry-picked from 3.0-stable
Revert "add Rails 4.2.0.beta1 to build for master"

This reverts commit c17d2476025a23d0b81a959ee4e90f0c16f405d6.
CHANGELOG catch-up