AddLoggingTarget bug. No way to log into a file having upper case letters in its path or name

There is currently a bug in cppTango preventing users to specify a file logging target having upper case letters in its path or filename.
This bug does not seem to be present in JTango.

For example, "file::/tmp/tango-tango/Starter/computer/Starter.log" will write into "file::/tmp/tango-tango/starter/computer/starter.log".

This bug was reported first in tango-doc#385