Several changes to support the allocation mechanism under SLC5 and more than 4 GBytes of RAM.

The analysis class TMemStatShow can now restrict itself to a subset of the address range or/and
entry range in the data Tree if the machine where the analysis is run does not have enough memory.
You can restrict the address range to be analyzed via TMemStatShow::SetAddressRange
You can restrict the entry range to be analyzed via TMemStatShow::SetEntryRange
the option "gnubuiltin" is not anymore the default in TMemStat.


git-svn-id: http://root.cern.ch/svn/root/trunk@37063 27541ba8-7e3a-0410-8455-c3a389f83636