Web UI features and API clean-up

• Download message in .eml format
• Cleaned up v1 API
• Defaults to in-memory storage
• Web UI and API improvements
  • Fixed UI rendering bugs
  • Message search and matched/total message count
  • Message list resizing and scrolling
  • EventSource support for message streaming
  • Better error handling and reporting
  • View/download individual MIME parts
  • Release messages to real SMTP servers
• Switch to go-bindata for asset embedding

In-memory storage and improved UI

• ESMTP server implementing RFC5321
• Support for SMTP AUTH (RFC4954) and PIPELINING (RFC2920)
• Improved AJAX web interface to view messages (plain text, HTML or source)
• Improved HTTP API to list, retrieve and delete messages
• Multipart MIME support
• In-memory message storage
• MongoDB storage for message persistence

First release

Basic functionality works:

• starts both SMTP and HTTP servers
• accepts SMTP messages
• stores parsed messages in MongoDB
• makes messages available via API
• has Bootstrap/AngularJS UI for viewing/deleting messages