Ensure that g_vasprintf will always abort on OOM and some docs fixes
This fixes a couple of the issues raised in #1622 (closed) which I discovered & was fixing independently when I came across that ticket.
These patches ensure that g_vasprintf will always abort on OOM, and add annotations to various parameters, and document that the returned string is guaranteed non-NULL unless using locale sensitive conversions.
Edited by Daniel P. Berrange