Fix broken ActionController#action_missing

A recent change introduced the assumption that all controller actions
are known beforehand, which is not true when using action_missing.
Revert "default the reaping frequency to 10 seconds"

mysql can't handle a parallel thread pinging the connection, so we can
get wrong results or segvs

This reverts commit 7cc588b684f6d1af3e7fab1edfa6715e269e41a2.
use `connect_poll` on pg so that reaping does not hurt the connection
Tidying up some require : removing useless sort and homogenizing with the rest of the code the wat the includes are done
Don't generate a scaffold.css if no-assets
Update other counter caches on destroy
Merge pull request #9837 from kjg/no_scaffold_css_when_no_assets

Don't generate a scaffold.css when --no-assets is specified
Merge pull request #9802 from newsline/fix-broken-action-missing

Fix missing action_missing

Conflicts:
	actionpack/CHANGELOG.md
Merge pull request #7706 from iangreenleaf/multiple_counter_caches

Update other counter caches on destroy
Fix copy table index test; Change == to ! on false in travis.rb
Merge pull request #9847 from vipulnsward/fix_sqlite_test

Fix copy table index test; Change == to ! on false in travis.rb
Merge pull request #9836 from Intrepidd/tidy-require

Tidying up some require and removing overhead caused by sorting
Adding a bang to method name of raise_on_type_mismatch.
Merge pull request #9853 from wangjohn/adding_bang_to_raise_method

Adding a bang to method name of raise_on_type_mismatch.