ui/razercfg: add support for "all" LED identifier

Can be used with -l to toggle on/off all supported LEDs.
fix typo
naga: add model to device name
naga: improve LEDs support

- refactorize code to make it easier to support different models
- add support for thumb grid LED on Naga 2014
taipan: minor cleanup
naga: fix resolution handling for 2014 version

- the Naga 2014 actually support a maximum scan resolution of 8200 DPI
  (instead of 5600 DPI for earlier models)
- the format of the resolution command is also different
naga: cleanup handling of protocol endianess

Use big-endian only to be consistent.
add HACKING.md

Contains a few pointers on how to sniff the original USB protocol with Razer official configuration software.