Automatic correct firmware download

This MR adds the ability to flash the appropriate firmware hosted in the repo:

bdaq53 --firmware BDAQ53

This command:

1. Inspects the bdaq53 installation to deduce firmware download location (tag/dev)
2. Downloads firmware
3. Decompresses the firmware
4. Checks for vivado installation
5. Uses vivado installation in tcl mode to flashed the firmware

If the filename exists locally it is preferred. If the firmware does not exist online a list of possibilities is provided. Useful error messages are given (programmer cable not detected, vivado not found etc.) Either vivado or vivado_lab (free) versions have to be installed for this to work. Thus far, this is only tested under Linux.