Fixes #9603 - fixed websockets_* set of settings

Fixes #11078 - Substitute find_all_by by where to comply with Rails 4

This commit takes away all instances up to this point of find_all_by to
improve Rails 4 compatibility. They are substituted by .where calls.

Refs #3809 - Style/blocks cop enabled

Fixes #10879 - reported_at column is NOT NULL

Allows for better optimisation of queries on PostgreSQL with
scoped_search.

Fixes #10526 - Support for Cisco POAP

fixes #10861 - Remove unused columns from the hosts table

• Serial - Never really used, probably can be refactored as kernel
  parameters.
• last_freshcheck, source_file_id - left overs from puppet old store
  configs compatibility that we no longer use, I assume no one is using...

Fixes #10409 - Rails 4 compatible changes with Rails 3

Fixes #10793 - rename old class name in taxonomy ignore_types

Fixes #10656 - Prevent audits on counter cache update

Fixes #10713 - improved backtrace logging

• full trace in 500 page in production shows really the full trace
• Foreman::Logging.exception as an unified entry point for exceptions logging
• the backtrace cleaner doesn't delete the plugins
• the orchestration exceptions gets the backtrace covered by logger...