Fix the fields_for method to include custom BootstrapForm options.

The FormBuilder.fields_for method only passes standard FormBuilder
options into the nested builder, causing the custom style, left, and
right options to reset on nested inputs.

This fix passes those options from the parent builder when using
fields_for while also allowing them to be overridden on the nested
fields.
Merge pull request #30 from awmichel/fix-fields-for-style-options

Fix for Horizontal/Inline Nested Fields
adding form-control class to all select helpers
revising *select fix to properly support options & html_options hashes
bumping to 2.0.1 to include fixes for fields_for and selects
Make name optional in FormBuilder#submit

This change makes bootstrap_form's submit consistent with Rails' one. That way we can write `f.submit` and make Rails get the proper submit name from i18n backend.
adding previously-removed 'primary' submit button helper
adding a better example to README for supplying your own css classes on submit buttons now that f.primary exists
Merge remote-tracking branch 'origin/master' into rails-4.1.0