* Fix checksum calculation for escape
 * Add vFlashWrite, vFlashErase and vFlashDone

Closes #159

GPIO port operations, single-parameter pin specifiers

Minichlink 20x/30x Fixes

Add standard input through the debug printf module.  Closes #168

Commits to wrong branch by accident.

 * Convert `sandbox` to `template`

Including:

 * Bringing in some changes to facilitate use on 307 and 203
 * Work with rv003usb bootloader
 * Windows cleanup
 * Random ch32v003fun bugfixes.

clobber all caller saved registers when calling an init_array

Ardulink - control power instead of reset