add failing test
Fix compatibility with 1.8.7 .
Refactor.
Merge pull request #1354 from namusyaka/fix-compat-with-1.8.7

Fix compat with 1.8.7
Automatically add multipart option to form_for if include file_field
Fix a problem that Breadcrumb#del does not work when name type is String.
Fix a few typos.
Fix how to receive multipart option
Add test file for breadcrumbs.
Remove unused lines.
Merge pull request #1356 from namusyaka/fix-breadcrumbs

fix a problem that Breadcrumb#del does not work when name type is String, add tests
Merge pull request #1355 from tyabe/multipart_form

Automatically add multipart option to form_for if include file_field
Refactor some codes.
Merge pull request #1357 from namusyaka/refactor-some-codes

Refactor some codes.
Add options to breadcrumb helpers.
Add test cases for breadcrumb helper options.
Add comment for Breadcrumbs#breadcrumbs.
Fix missing slash in form_helper.rb
Fix missing slash in asset_tag_helpers.rb
Merge pull request #1360 from namusyaka/fix-missing-slash

Fix missing slash in comments