adding comment specifying that cattr_accessor also supports instance_write and instance_rader option

Revert "Frameworks are loaded in application.rb rather than config.rb according to Rails 3 conventions."

This reverts commit 1793b214.

This commit had no risk, but docrails has a hard rule about touching code.
The contribution is appreciated, I hope you do not mind this technical
revert. I'll apply that to master with proper credit.

amended Contributing to Rails guide to advise to use bundler v1.0 to avoid error messages with bundler

Signed-off-by: NWincent Colaiuta <win@wincent.com>

This resolves issues for libraries which use '_' prefixed keys in their
attributes hash, such as Mongoid. A key like "_id" or "_type" will no
longer be converted to "<-id>" and "<-type>".
Signed-off-by: Nwycats <wycats@gmail.com>

[#5170 state:resolved]
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

They're deprecated since 2008. It's time to get rid of them.
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NWincent Colaiuta <win@wincent.com>

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Signed-off-by: NJosé Valim <jose.valim@gmail.com>

Fix a bug where requires inside of autoloads were being added to the autoloaded_constants list, causing mayhem. [#5165 state:resolved]

Gemfile now makes use of platforms calls with blocks instead of elsif logic to define dependencies over specific platforms