Surface through D-Bus, fix camera ordering.

Hacky solution to bulk-export a single session object through D-Bus,
verified with these commands:

dbus-send --print-reply --type=method_call
    --dest=com.blackmagicdesign.QAtemConnection /QAtemConnection
    com.blackmagicdesign.QAtemConnection.setDebugEnabled boolean:true

dbus-send --print-reply --type=method_call
    --dest=com.blackmagicdesign.QAtemConnection /QAtemConnection
    com.blackmagicdesign.QAtemConnection.debugEnabled

Also fix bug where ATEM Production Studio 4k swaps the byte ordering
on preview/program camera numbers.  Fix build error now that usleep()
is marked as protected.