Merge pull request #138 from andrew-elder/staging

lib: controller: function end_station_imp *at(size_t i) now uses lock_guard
cmd_line: view details command now operates on selected configuration
Added Prerequisites and steps to build on OSX
AVB interface, Clock Domain, and Stream Input GET_COUNTERS command functional
cmd_line: view details command now operates on selected configuration
Merge pull request #142 from vronchetti/issue_109

Issue 109
Get Counters - AVB Interface, Clock Domain, Stream Input (+2 squashed commits)
Squashed commits:
[a139745] gitignore update for Doxygen update
[be824c9] comment error in cmdline.h
adding log messages for invalid counter names, entity specific counter labels
Merge pull request #144 from vronchetti/vr-counters

Counters
adding control descriptor
eliminated whitespace
formatting changes for uniformity
whitespace fix
Merge pull request #146 from vronchetti/controlcommands

Control commands
change "counters" to "counter", fix a typo
Merge pull request #147 from vronchetti/CountersSyntaxCleanup

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

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

Duplicated names