ToDo for 3.0

[tknerr]

Todo's for the 3.0 final release:

• [x] make recreate_dirs work again (57d07c1fb3127cf959a2300bba8a91b24759cca2)
• [x] vagrant docker remote host patch: fix multi-vm portforwarding issue (#110)
• [ ] cache baseboxes for faster builds (#93)
• [x] add proxy on/off script (#102)
• [x] conditionally b2d download if iso not present (95e01cf4efa325d98fd0c737b9e1f777112c1afe)
• [x] add vagrant-winrm plugin
• [x] update to terraform 0.5