Use uppercase for `OS` env variable

This is used for Windows system where this environment variable
is case-insitive. However, if Windows/Cygwin is used, Python
is case-sensitive and the conditions fail.
Add output_loglevel param to cmd.run* functions

Also deprecates the "quiet" param, and alters the logging behavior of
cmd.run* and cmd.retcode. cmd.run_all no longer is the only one of these
that logs the cmd output at loglevel ERROR if the retcode is nonzero.
If the command has a nonzero exit status, then the minimum loglevel at
which the output will be logged is ERROR (if the output_loglevel was set
higher, than that level will be used).

The "quiet" loglevel still works as before, suppressing all output
logging for the command, even if there was an error.
Fix refs to cmd.run* with quiet=True

This changes these references to use output_loglevel='quiet'
Lower loglevel for verbose pkg mgmt commands

This uses the new output_loglevel argument to force these commands to
log their output to loglevel DEBUG. Note that any error encountered in
running these commands will log the output at loglevel ERROR.
Add 'critical' loglevel to salt.log.setup.LOG_LEVELS
Fix spelling error
First attempt at abstracting ZeroMQ communication.
Laying the groundwork for overstate unit testing.
Pylint
Expose the highstate while we're building it, to let pydsl include correctly.
Unit test for including a state multiple times using pydsl.
Missing newline
Correctly pass kwargs through to wheel.call_func

The change in 1de6204 broke what format_call() expects in
wheel.Wheel().call_func().
Made state_highstate more useful.
more debug verbose output for git.latest
Merge pull request #9230 from Psycojoker/develop

more debug verbose output for git.latest
format instead of printf
More tests.
added default value of 4096 bits to config for master and minion RSA-Key
modified key-generation for master and minion to use self.opts['keysize'] instead of defaulting to 4096
Add instructions on using pylint to the Salt style coding style guidelines.