Now 'nfdc foo help', 'nfdc foo --help', and 'nfdc foo -h'
are all accepted as synonyms of 'nfdc help foo'.
Additionally, '--version' can be used in place of '-V'.
Change-Id: I070bb0ea9231a2642c40938377f1e9af2630b34e
Refs: #4503
* use same underlying type for ParseMode and AvailableIn,
to avoid potential errors when converting between them
* simplify AvailableIn stream output operator with text::Separator
* allow CommandParser::addCommand to accept bitwise OR'ed modes
* qualify nfdc logging sources with 'nfdc.' prefix
refs #3780
Change-Id: I2eee3d562184daf27305c2d5f2892637b63421c2
Davide Pesavento
Junxiao Shi