Win build

### Changelog 

* Add `configure.ps1`, `run.ps1` and `test.ps1`
* Add `setup.py` that configures py2exe and a bootstraper script that bootstraps OpenBazaar 
* Make openbazaar single-process in a frozen environment (like in an exe build where running python.exe is not possible)

### Usage

* In order to run OpenBazaar from its sources in windows, one must have Visual Studio 2008 installed first
* After checking out the source running `configure.ps1` will install python, GnuPGP and OpenSSL in the bin directory and install all required packages
* NOTE: All windows systems come with the option to run PowerShell scripts disabled. To enable running PowerShell scripts the user must run `Set-ExecutionPolicy RemoteSigned` first in the PowerShell prompt.
* `run.ps1` runs OpenBazaar
* In order to generate an exe distribution, the command `configure.ps1 exe` calls py2exe. The result files are written in \installers\windows\dist_exe directory