Change definition of "maxsize"

The logger keyword "maxsize" takes a numerical value which is represented as a 32bit unsigned integer.
This allows for a maximum file size no larger 4G.
It may be usefull to:
a) Be able to define larger files.
b) To be able to use the acronyms 'M' and 'G' as in "500MB" or "6G" within the definition .
c) Or just issue a warning when defined value is out of range set it to 4G and update the ARM.

RT 19478