Added use of a local PACKER_CACHE_DIR

If there is no global PACKER_CACHE_DIR set, then use a local cache dir
".\packer_cache" for all your build.
Merge pull request #1 from DieterReuter/fix/master/fix_cache_dir_in_make_bat

Added use of a local PACKER_CACHE_DIR
Fixed image name for Windows Server 2012 R2 Preview

/IMAGE/NAME = Windows Server 2012 SERVERDATACENTER
create local packer_pache dir if not exists
reverted last change
fixed winrm on win7, change network to private
fixed quotes
no swap
fixed winrm on win8.1, change network to private
use x86 cygwin on Win 2012 R2, x64 does crash
started work to replace cygwin sshd with freesshd

but packer does not connect to freesshd. To debug this I have added an
'sleep' at the end of the install-freesshd.bat script. You then can
ctrl-alt-delete and open task manager, then start a cmd.exe so you can
investigate the vm.
added chef client again
freesshd does not work, added notes
uninstall cygwin before shutting down vm
bigger disk, no chef at the moment
cleaned up
fixed pathes
remove cygwin from disk, winrm open

remove cygwin from disk, open winrm for public on win81, install chef in
win7 / win8
turn off some win8.1 cpu load tasks
reverted some changes, keep services as is