[dd86k]

Introduce the Easy API with a partial rewrite.

The Easy API is a new set of modules that features a debug loop using message-based communication underneath. It will be something similar to libcurl's Easy interface, which will help manage remote processes and ease the integration process for Aliceserver in a multithread environment.

Breaking changes include mostly the debugger module, which gets rid of callbacks to state an example. Removing callbacks help with locality (otherwise, it's sync hell across several callbacks). However, callback(s) will be provided with the Easy API, because the event thread will be separated from the debugger thread.

There are other changes coming that removes some older cruft and hacks.

In summary:

• Introduce the Easy API via the adbg.easy module.
• Introduce thread, mutex, semaphore wrappers for internal use.
• Add adbg.util.mailbox for messages-passing for internal use.
• Redo the terminal library to avoid depending on stderr (a recurring issue regarding linking with older compilers on Windows).
• Make error module thread-safe(r) (by using TLS).
• Remove process hacks introduced in adbg.debugger.

It'll be a very messy, but overdue, PR.

[dd86k]

Merged locally.