download verpatch and add version info to bsdtar

As users still struggling upgrading from vagrant 1.5 to 1.6 as mentioned in mitchellh/vagrant#3674, I thought about adding a version resource to the two missing binaries bsdtar.exe and bsdcpio.exe so that the MSI installer does install the current versions.

I found a small tool to patch a version info into exe files at codeplex: [verpatch](http://ddverpatch.codeplex.com)

A sample call would look like this:

```
verpatch.exe bsdtar.exe /va 2.8.3.0 /pv 2.8.3.0
```

@mitchellh what do you think about doing it that way?

I know it is some kind of monkey-patch, but I don't know where these binaries are maintained to ask to add the version infos there. So it might be better to have it fixed for Vagrant 1.6.3 this way.

Another idea is to patch the vagrant-files.wxs file generated by heat.exe, but I do not have a working WiX environment to check it out.

I could only test the script in a vanilla windows box and put the lines into the package.ps1 before building the MSI files, so I hope this is the right place in the build process. The script catches the version number from the bsdtar.exe itself, so it should be some kind of update-proof.

A sample output of my test environment looks like this:

```
Vagrant temp dir: C:\Users\vagrant\AppData\Local\Temp\1\epc32kdm.uya
Downloading verpatch 1.0.14
Unzipping verpatch
True
Patching version 2.8.3.0 into tst\embedded\gnuwin32\bin\bsdtar.exe
Patching version 2.8.3.0 into tst\embedded\gnuwin32\bin\bsdcpio.exe
Done
```