fix_duplicating_css_ids_bug: generate id with prefix
Limit the TableCheckboxToggler to 'top level' tables.
Merge pull request #1993 from fd/master

Limit the TableCheckboxToggler to 'top level' tables.
Merge pull request #1991 from joxxoxo/fix_duplicating_css_ids_bug

namespace hidden field IDs
refactor breadcrumb helper

+ ActiveRecord#find accepts a string (even when searching for a numeric ID)
+ removed unnecessary begin/rescue/end block; used nil-returning method alternatives
+ use `path` instead of `fullpath` to get rid of query parameters (we already leave them out)
Merge pull request #1938 from Daxter/refactor/breadcrumb-helper

Refactor breadcrumb helper