Dynamic finders should use the ActiveRecord::Base::find method instead of ::find_initial, :find_last, and ::find_all.

This is so when people override ActiveRecord::Base::find, the new ::find method will also be invoked by the dynamic finders.
Associations for instance do go through ::find, so this makes it more consistent.
Also removed the unnecessary deprecation silence blocks.

Signed-off-by: Michael Koziarski <michael@koziarski.com>

[#1162 state:committed]