CP/M for OS X

Minor updates to keep track with macOS; this build: * adds M1 support; and * enables the hardened runtime, permitting this to become a signed app.

Corrects a bug introduced by 0.7.0 that caused a very high number of applications not to launch. Specifically: * the BIOS start address is now 256-byte aligned; * the (fake) BIOS itself starts with just a bunch of `.addr JMP addr` statements because applications like MBASIC steal the target addresses from those JMPs and dynamically reprogram themselves; * but the loop that installs those JMP statements was inadvertently overflowing its addressing range and overwriting the main from-here-to-BIOS JMP at address 0. The latent error that caused this became apparent with 0.7.0 because the start address for the BIOS is no longer picked as a function the number of `JMP` statements that need to be stored.

Aligns the BIOS entry point to a 256-byte boundary, resolving issues with WordStar 4 and various other pieces of software.

Permits a little extra room for rounding errors in text output, solving potential disappearance of the final column and row of text.

Improved default drive handling; now using the proper OS X text highlight colour.

This release corrects an error in file control block handling that could prevent some software from locating its files.

Added text selection for copy operations, improving clipboard integration.

A very hasty release; this fixes a regression in file creation.

This release fixes a mistake that caused applications to think the user had specified valid arguments when launching an application.

This release includes an attempt at enabling write access to your filesystem. So be careful. No guaranties.

Added an application icon, added support for multiple drives via drag and drop, switched to amber text to enable subpixel rendering, fixed an issue with loading files that aren't a multiple of 128 bytes in size.

Added support for BDOS call 10 — buffered console input — and resolved an issue whereby you'd have fully to quit and reopen CP/M for OS X to reopen a specific CP/M program.

An extremely early build; this attempts read-only execution of CP/M applications. Even those BDOS and BIOS functions that are implemented probably remain far from conformant. To use, just put this app anywhere on your system then find a CP/M program and double click to launch it.