Call String#gsub with Hash directly
Merge pull request #9554 from tmm1/string-gsub-hash

Use 1.9 String#gsub syntax
change useless gsub to delete
strong parameters example for default values using `fetch`. [ci skip]

Origin: #9534.
example for `accepts_nested_attribtues_for` and strong parameters.

Closes #9558.
Merge pull request #9556 from senny/strong_params_examples

strong parameters example for default values using `fetch`.
Fix typo in AC overview guide [ci skip]
Merge pull request #9557 from bonsaiben/useless_gsub

Change useless gsub to delete
Routing match `via` option requirement exception message made more explicit
Merge pull request #9561 from inossidabile/explicit_match_via_requirement_exception_message

Routing match `via` option requirement exception message made more explicit
assigning '0.0' to a nullable numeric column does not make it dirty
Merge pull request #9042 from senny/9034_float_0_0_is_always_dirty

Assigning '0.0' to a nullable numeric column does not make it dirty

Example:
    product = Product.create price: 0.0
    product.price = '0.0'
    product.changed? # => false (this used to return true)
    product.changes # => {} (this used to return { price: [0.0, 0.0] })
change useless gsub to tr
Merge pull request #9564 from robertomiranda/useless_gsub

change useless gsub to tr