Support NuGet in ZipEngine

Requirements:
- Main nuget feed in settings (done)
- Alternative nuget feed
- download package from http feed (done)
- store packages in file system by versions (done)
- construct and download by direct url

Settings:
- nuget feed (http) (done)
- http proxy settings
- cache dir (done)
- package id (done)
- package version (done)
- in package base dir (done)
- autodownload new version



