REQ_encToJackClient

top level reqs
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the executable shall read values from encoder(s).
the exec shall print the encoder values to stdout
the exec shall act as a jack client
the exec shall convert the encoder values to MIDI msgs
the exec shall push the midi msgs to a jack server
the exec shall be configurable through cli args

the exec should not require to store any values in cfg file for next run

input args reqs
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-g gpioEncA,gpioEncB: gpio numbers for the pairs of encA, encB connections. 
    one pair per encoder. This options should be allowed multiple times
-c ctrl#: controller number. corresponds to -g. for each -g there should be a -c.
-n jackname: name of jack client
-p <no arg>: print to stdout instead of loading the jack client (the 2 are mut.ex.)


operational reqs
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-the exec shall be started with some cli args
-the exec shall be closed gracefully through a SIGTERM signal