Make varint in gbt submission a stack object.
Minimise the amount of heap memory allocations/frees when submitting gbt shares.
Fix various ava2 build issues generically
Update NEWS
Bump version to 4.2.1
Add support for other usb3 hubs on windows
Trivial variable reuse
Increment total_work under control lock.
Revamp the ageing crufty hashmeter code to have proper exponential decaying values and store rolling 1/5/15min hashrates.
Use the extra status screen real estate better, displaying rolling 1/5/15min average hashrates as well.
Add 3 rolling average hashrates to API output for summary and devs.
Put sanity check on decay_time to prevent updates with no time