This makes sure that, in a HABTM association, only one join record is craeted.

Make polymorphic_inverse_of in Reflection throw an InverseOfAssociationNotFoundError if the supplied class doesn't have the appropriate association. [#3520 state:resolved]
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Provide a slightly more robust we_can_set_the_inverse_on_this? method for polymorphic belongs_to associations. [#3520 state:resolved]

Also add a new test for polymorphic belongs_to that test direct accessor assignment, not just .replace assignment.
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Get rid of a duplicate set_inverse_instance call if you use new_record(true) (e.g. you want to replace the existing instance).
Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Signed-off-by: NEloy Duran <eloy.de.enige@gmail.com>

Added Object#presence that returns the object if it's #present? otherwise returns nil [DHH/Colin Kelley]

Added default .gitignore (this is just recognizing Git market share, don't throw a hissy if you use another SCM) [DHH]

Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

Added shorthand for match 'products/overview' that expands to match 'products/overview', :to => 'products#overview', :as => 'products_overview'