Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

The comment about memory ownership in uuid_t::to_string
was misleading as on most platforms the buffer is a field
of the object;
The string allocated in UuidToString() wasn't properly freed
with RpcStringFree()
Signed-off-by: Taras Shpot <taras.shpot@eleks.com>