V0.88.28

[dwash96]

Addresses:
#184

Includes:

• Fix hang from issue 184 (above) by making sure output stream is None'd on finish, even if the generation task errors
• Refactor local tools to implement a common BaseTool abstract class as a precursor to a plugin system
• ReplaceText tool to display a diff of its output so it's more legible what is changing during generation
• Update with Aider main