Merge pull request #146 from vronchetti/controlcommands

Control commands
Merge pull request #147 from vronchetti/CountersSyntaxCleanup

change "counters" to "counter", fix a typo
Merge pull request #149 from vronchetti/CountersSyntaxCleanup

counter valid and block swapped
Merge pull request #150 from vronchetti/CountersSyntaxCleanup

Duplicated names
Fix 'get counters STREAM_INPUT idx'

Fix indexes for STREAM_INPUT_FRAMES_RX and STREAM_INPUT_FRAMES_TX
in stream_input_descriptor_imp::get_counter_by_name().