remove more conditions for Fiber in ruby19

fiber is available in ruby19 condition removed

ruby 1.8 ActiveSupport BasicObject no longer available

remove condition since to_time always available in ruby19 DateTime

Fix #2572 and define fixture table name in the associated model

AS::Callbacks: remove __define_runner

refactor Range#include? to handle ranges with floats

Renamed "fixture_name" to "accessor_name" and made fixture names in the form "admin/users" be used as the key for the hashes @fixture_cache and @loaded_fixtures.

Previously the variable "fixture_name" here was getting a value of the form "admin_user", and this value was then used as the hash key.

Made the fixture's table name be taken from its model class whenever this class responds to table_name, instead of inferring it sometimes from the fixture's pass.

The previous behavior seemed buggy because it depended on whether the model class was passed as a constant or as a name string.

Improved Fixtures#initialize.

This solves an issue with set_fixture_class class method caused by create_fixtures method's overwriting passed to it fixture model classes, when the fixtures are "namespased": foo/bar or admin/users.

The idea is to use "foo/bar" string as the name and identifier of a
fixture file bar in directory foo.  The model class of the fixture is either set with set_fixture_class method, or otherwise inferred from its name using camelize method.

Also a bug is fixed in lines 487-489 when the table names were guessed by substitution from the fixture file names, ambiguously called  table_names, instead of being taken from fixture attributes.  Now they are taken from attributes.

I plan to submit another fix so that the fixture's table name (for
example foo_bar) be defined by the fixture's model whenever possible,
instead of inferring it from the fixture's name ("foo/bar").

Test using fixtures with random names and model names, that is not following naming conventions but using set_fixture_class instead.

It is expected that the table name be defined in the model, but this is not explicitly tested here.  This will need to be fixed.

rather than casting