Investigate: Refactoring the ant build into a ps1 build

[lizbaron]

• BuildtSQLtZip.ps1 is at a minimum overloaded and does more than just build the tSQLt.zip file. This needs to be refactored, perhaps consider using classes.
• We should consider automatically adding the version to the name of the public artifacts, including the following. And generating the names should live in one place.
  • tSQLtSnippetsSQLPrompt_Vx.x.xxxx.xxxxx.zip
  • tSQLt_Vx.x.xxxx.xxxx.zip