[xml] threads and xmlInitParser

[Fredrik Arnerup <e97_far elixir e kth se>]

Hello,

I had a threading related problem with the saxparser that I managed to
resolve by putting a call to xmlInitParser() in main().
However, the problem also disappeared when I put a call to xmlInitParser()
inside each thread before starting the parser.

I realize this is not what the docs say I should do, but can I expect
xmlInitParser() to work even if it is called from a separate thread and can
I call it more than once?

I ask partly for my own sake and partly because I hope to produce a patch
that would make libxml++ more thread safe.

/Fredrik Arnerup