Oracle DataBase module

execution module; can connect to multiple dbs described in pillar and
run sql-query
fix some pylint warnings
fix some pylint warnings
rewrite dict comprehension
allow hierarchical credentials

used for store 'default' and 'sys as sysdba' database connection:
my_db:
uri: user/pass@host/db
dba:
uri: sys/syspass@host/db as sysdba

oracle.run_query my_db:dba "select * from dba_users"
avoid confusing with salt-cloud
rewrite some sentences
add document for installing salt-cloud on Ubuntu

as saying that salt cloud is merged to Salt may cause confusing
make user thinks no need to install salt-cloud pkg
add basic usage doc for salt-cloud
Consolidate duplicate bind docs of docker.running

The documentation for `docker.running` had two divergent definitions for the `bind` argument. I've consolidated them and added some explanation of the two forms.
Clean keyboard exit in test suite
Add missing <ul>[…]</ul> around list elements in sidebar TOC.
Updated the contributing guide with a link to the documentation contribution docs.
Fixed some spacing issues in the contributing docs.
Don't calculate sum on stat
Adding support for single LaneStack for RaetChannel
Merge remote-tracking branch 'upstream/develop' into sam_raet_50
Merge pull request #14083 from hvnsweeting/hvn-doc-update

Salt virt/cloud doc update
Merge pull request #14092 from eykd/patch-2

Consolidate duplicate bind docs of docker.running
Merge pull request #14100 from cachedout/test_exit

Clean keyboard exit in test suite