Continue to improve windows support

Small fix for better tockloader support on windows.

Basic Windows Support

Two changes in this release:

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

More JLink Customization

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

RTT Support and More Default Boards

In this release:

• Preliminary support for listening to printf() from a board through Segger's JLinkRTTClient tool. This requires that the JLink tools be installed. tockloader listen --jlink to use.
• Add nrf51dk, launchxl-cc26x2r1, and ek-tm4c1294xl as known boards.
• Allow apps to be installed from URLs.

Stable Basic UI, Many New Features

This release brings Tockloader 1.0! The basic UI is now stable (install, uninstall, etc.). The newer functions are not guaranteed to be stable, but there are likely few if any people using them regularly.

Changes

• --jtag is deprecated and replaced with --jlink.
• Tockloader can parse the crt0 header used by C apps.
• Added --no-bootloader-entry to tell tockloader to assume the board is already in bootloader mode.
• Added support for chip specific flash page sizes.
• listen can print timestamps and line counts.
• install can fetch apps from a server.
• Added support for OpenOCD.

Improved Serial Escape Handling

Version 0.9.0 of Tockloader brings these new features:

• The command dump-flash-page can now accept a page number in hexadecimal.
• New command called read for reading arbitrary ranges of flash memory.
• An interrupted listen session will now resume listening on the same serial device as it started on. This is relevant when there are multiple bootloader supporting boards attached.

And these bug fixes:

• Escape characters in the serial bootloader are now handled properly. Before they could be escaped multiple times.
• App binaries are now checked to ensure they aren't longer than their header says they should be.
• Flags specified before/after the command are handled properly.

Support for `appaddr` attribute

This release:

• Adds support for determining where the start of applications is using a bootloader attribute called appaddr. This is considered temporary until kernel attributes are supported and this setting will be moved there.
• Includes some known Tock supporting boards so that if you pass --board Tockloader will use the known boards to fill in --arch and --jtag-device.
• Includes more debugging help when the necessary board properties aren't passed to Tockloader.

Update TBF Header

• Slight change to TBF header (now padded to 4 bytes).
• Also don't change baud rate unless told to. This needs more testing.

Fix unecessary warning

Since we use an invalid header to mark the end of apps, tockloader was always printing warnings about unknown TBF versions. This removes that warning printout.

TBF Header V2 Support

This release adds support for the new version of the Tock Binary Format header, version 2!

Also:

• Refactor the code to split classes into individual files.
• Detect multiple tockloader instances and pause tockloader listen while another tockloader command completes.
• Add install --erase to erase all apps before installing a new one.
• Add autogenerated docs.
• Improve printout formatting.