The itk::TimeProbe constructor ends up calling
itkResourceProbe::GetSystemInformation, which reads things like the
hostname, the number of CPUs and so on. On Linux it parses /proc/cpuinfo
for that information.

OTB doesn't really need all those fields for a simple timer that's only
used in a couple of places. This commit adds a replacement for that.

As for the benchmarks, 100 000 instantiations of itk::TimeProbe take
about 9.5 s on my computer. I suspect it's somewhat slower on a server
with more CPUs. So this doesn't bring a huge performance improvement,
but it might help in cases where a large number of high-resolution
images are being read. The time for the same number of otb::Stopwatch
instantiations is 4 ms.

The context for this change is a project where we process time series of
medium to high resolution images over large areas. The TimeProbe in
otbGDALImageIO was sometimes showing in the profiles.

A relevant discussion can be found at
https://groups.google.com/d/msg/otb-developers/IvsFzSgRojo/0sMeEIZgCQAJ .

BUG: EnableParameter method should be used to activate EmptyParameter in Python API in the ref documentation

BUG: Fixing bug #1467. No Update() should happen on filters whatsoever, unless you know for sure that the Udpate() call will not load whole image in memory. No local pointers to filters are allowed (because the streaming pipeline disappears at the end of the method)