Tockloader

This release of Tockloader is designed to support the Tock Bootloader on the Nano 33 BLE board based on the nRF52840. Since that board does not have an FTDI chip, the bootloader uses the nRF52's USB peripheral. This requires a new method for entering the bootloader, and Tockloader now supports setting the baud rate to 1200 to instruct the chip to enter the bootloader.

Other changes:
- Moved some output to only on `--debug`.
- Added support for TABs that contain TBFs of different lengths.
- Added microbit v2 over openocd as known board.
- Added set start address command.

This release primarily updates Tockloader to support Tock apps that are compiled for specific addresses in flash and RAM. Tockloader can use TAB files that include multiple copies for the same architecture but with different addresses. It can also try to arrange apps so that multiple fixed address apps can be used at the same time.

It also includes some output formatting updates.

Updates included in this release:

- Add boards:
- Arty 100t FPGA + SiFive E21 core
- HiFive1 board
- EDU-CIAA
- Add customization options in Tockloader:
- Can force an app to be a minimum size (useful for nRF52 chips with 4k flash pages)
- Flexibility for app ordering in flash
- More improvements for Windows
- Use logging mechanism rather than raw print(). Provides prefixes for printed output.
- Tockloader listen with RTT now uses the `--rtt` flag.
- Tockloader listen no longer interrupts an existing tockloader listen.
- More flexibility for jlink and openocd commands.
- Add `--bundle-apps` to flash all apps as one bundle.

Small fix for better tockloader support on windows.

Two changes in this release:

1. `tockloader` runs on Windows, but without support for pausing and resuming`tockloader listen` (and perhaps other functionality).
2. Improvements for the CC26x2 based boards.

This release adds the ability to configure the JLinkExe interface and speed. It also provides better support for the cc2652.