v0.2.0 alpha release of Open PowerShell

Supports Windows, OS X, Ubuntu 14.04, and CentOS 7.1.

Major changes since v0.1.0:

- .NET Core packages are build 23907
- `System.Console` readline is fully functional
- Tests pass on OS X
- `Microsoft.PowerShell.Platform` module is available
- `New-Item` supports symbolic and hard links
- `Add-Type` now works
- PowerShell code merged with upstream `rs1_srv_ps`
