Add max2837_set_lpf_bandwidth() function to choose available LPF filter bandwidth based on bandwidth in Hz.
Change configuration of MAX2837 to set LPF_EN and FT at max2837_setup(), not in max2837_rx() or max2837_tx() (which was overriding prior filter configuration).
Implement switching between several supported sampling rates for Jellybean and Jawbreaker.
Commit bits of the Si5351C USB request support that I apparently missed in a prior commit.
Initialize MAX5864 earlier, in "transceiver" mode (where both ADC and DAC are active), and then shift SSP1 into MAX2837 mode and leave it there, for faster tuning and RX/TX switching.
Initialize transceiver mode at SET_CONFIGURATION time.
Provide switching of transceiver mode via vendor request.
Provide read/write access to MAX2837 registers via vendor requests.
Python utility to dump MAX2837 registers.
Python utility to switch transceiver RX/TX mode.
Relocated USB buffers to be split across two AHB memory regions, so that USB endpoint priming doesn't choke SGPIO transfers.
Added code to configure 2.4GHz front-end.
Changed USB and SGPIO priority levels (probably unnecessary because sample corruption was due to USB priming bursts).
