Float type casting with I18n support.

Example:

    # Before (factor is a float column)
    Post.new(factor: '1,234.567').factor
    # => 1.0

    # After with default locale (separator: '.', delimiter: ',')
    Post.new(factor: '1,234.567').factor
    # => 1234.567

    # After with other locale (separator: ',', delimiter: ' ')
    I18n.locale = :pl
    Post.new(factor: '1 234,567').factor
    # => 1234.567