Object#in? also accepts multiple parameters

added tests to #3763

allow using orm_instance without invoking orm_class in generators

Tests added for monday and sunday 

Reference commits : 
a8f2860d
80ac4dc6

A recent change to beginning_of_week and end_of_week added an argument
that can be used to specify the week's starting day as a symbol. Now
these methods were aliased as monday and sunday respectively which as a
consequence of the argument addition, made calls like obj.monday(:sunday)
possible. This commit makes them methods on their own.

Warning removed unused variable

mentioned about OS X and windows usually having a JS runtime

Rationale: this is more readable if serveral queries
are involved in one call. Also, it will be possible
to let AR log EXPLAINs automatically in production
mode, where queries are not even around.

beginning_of_week extended in both Time and Date so that to return week start based on start day that is monday by default

Updating newline fix to maintain existing linebreaks and indentation and...

middlewares should have configurable logger

This implements the ActiveModel::Serializer object. Includes code, tests, generators and guides.

From José and Yehuda with love.

Conflicts:
	railties/CHANGELOG.md

Added tests for #3751