Support WinRM communicator, offline builds, more

* Update to work with WinRM communicator
  (https://github.com/mitchellh/packer/pull/1175)
* Support offline builds by searching for files locally, before
  attempting to download them
* Strengthen error checking/reporting
* Add `floppy/unzip.vbs` to remove 7zip requirement
* Add `lessmsi` to avoid *installing* 7zip to extract files from iso
* Prepare for https://github.com/mitchellh/packer/issues/1181
* Move most cleanup/delete code to `clean.bat` to aid debugging
* Download VMWare Tools ISO, if not available locally
* Download Virtualbox Guest Additions ISO, if not available locally
* Add `CYGWIN_MIRROR_URL` to `_packer_config.cmd`. Fixes #12
* Add 5 other useful variables to `_packer_config.cmd`
* Add `_packer_config_local.cmd` (similar to `Makefile.local`)
* Allow many script variables to be overriden in `_packer_config*.cmd`
* Standardize scripts to use same logic, and case, throughout

* Wait until ssh service is stopped before opening port 22
* Wait until winrm service is stopped before opening port 5985
* Wait until installation is done before starting winrm service
* Replace `timeout` with `choice`, as `timeout` sees mouse click as
  keypress in `00-run-all-scripts.cmd`
* Fix `_download.cmd` to work if filename differs from URL
* Uppercase environment variable names in `.ssh/environment` to be
  consistent with Cygwin standard
* Replace `%TEMP%` with `%SystemRoot%\Temp` in `openssh.bat`
fix sdelete fail due to start prefix
fix when cm=nocm, cm_version is not defined
Improve debugging logic, minor bug fixes, etc.

Log floppy script output via `tee.js`
Include floppy script output in packer log via `dump-logs.cmd`
Beep on error
Standardize ssh password as D@rj33l1ng due to password requirements
Fix `sshd_server` username
Don't abort if shared folders are not available
Fix `pushd` in `script/vmtool.bat`
Fix small typo in `floppy/zz-start-sshd.cmd`
Undid sshd_server username fix as it just masks the issue
Add `ping` at end of scripts to force script output
Fix test-box failure by adding "config.vm.guest = :windows" to tpl files

Remove chkdsk from zzz-debug-log.cmd as it hangs on occasion
Change fatal to warning in save-temp-dirs.cmd
Bumping version of openssh
Reverting back to previous version - VMware tools don't install on Win 8.1/8
Merge branch 'support-winrm-better-error-handling-etc-v2'