Add comment on suspicious (thread-safety wise) part of the code
Add comment on suspicious (thread-safety wise) part of the code

Conflicts:
	io/io/src/TBufferFile.cxx

tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot