[rfc] threadsafety of library documented

[cz172638]

is hard to figure out if library is threadsafe or not.
it would be good to have it documented (yes/no. if so, what have to be considered and so on).
thanks

[ypo]

Thanks for your report,
I agree I should document that
Today the FLUTE sender is thread safe, the FLUTE receiver is not

[cz172638]

thanks for answer.
for now flute's 'thread safety' as is today is sufficient.