Interface improvements

• Improves the license migration flow to Paw 3 (please migrate your legacy licenses to Paw 3 licenses, if not already done)
• Improves the completion window, which was showing up too often in multiline fields
• Other minor theme and interface fixes

Paw Cloud

• Adds ability to save a cloud project to a local file (in File menu)

Fixes

• Fixes a major crash on macOS Sierra
• Fixes tab bar in dark mode on macOS Sierra
• Fixes exchange history menu when there are too many items
• Fixes issues with JSON parsing
• Fixes issues with importers & exporters on OS X Yosemite