Packaging script Windows build handling

[sparrc]

Packaging script changes appear to have caused some problems with the windows zip packages. There are two problems:

• It is preserving Linux paths:

$ unp ./telegraf-0.11.0-1_windows_amd64.zip
Archive:  ./telegraf-0.11.0-1_windows_amd64.zip
   creating: etc/
   creating: etc/telegraf/
  inflating: etc/telegraf/telegraf.conf
   creating: etc/logrotate.d/
  inflating: etc/logrotate.d/telegraf
   creating: usr/
   creating: usr/bin/
  inflating: usr/bin/telegraf.exe
   creating: usr/lib/
   creating: usr/lib/telegraf/
   creating: usr/lib/telegraf/scripts/
  inflating: usr/lib/telegraf/scripts/init.sh
  inflating: usr/lib/telegraf/scripts/telegraf.service
   creating: var/
   creating: var/log/
   creating: var/log/telegraf/

• It is using the wrong default config file, it should be using etc/telegraf_windows.conf, not etc/telegraf.conf

Previously, the windows zip package was just a single directory with two files: telegraf.exe and telegraf.conf (copied from etc/telegraf_windows.conf)

See http://get.influxdb.org/telegraf/telegraf-0.10.4.1-1_windows_amd64.zip