Fix rx buffer allocation

[zuckschwerdt]

• Fix activateStream loosing the first buffer
• Fix set_buffer_size failing to alloc the default size buffer
• Fix log format about selected buffer size

[zuckschwerdt]

@vsonnier please test and rebase your changes, this will go in asap as hotfix.

[vsonnier]

@zuckschwerdt Go on, push that on master I'll manage #14 rebase afterwards because those changes are from your repo, so its no very practical.

[vsonnier]

Nevermind, I've manually merged the (very small) difference in #14.

[zuckschwerdt]

Ok, I'll let this sit for a day so other people can get a word in if needed.