New format() options "uppercase"|"lowercase"

[Rik]

All,

I have changed format so that it is Matlab-compatible by default.  This
meant treating the arguments to format in a case insensitive manner.  As
such, the Octave extensions 'short E', 'long E', 'short G', 'long G' no
longer change the case of the 'e|E' in exponential notation.

Instead, there are now two new options to format for which I will quote
from the documentation:

     The following two options affect the display of scientific and hex
     notations.

     'lowercase (default)'
          Use a lowercase 'e' for the exponent character in scientific
          notation and lowercase 'a-f' for the hex digits representing
          10-15.

     'uppercase'
          Use an uppercase 'E' for the exponent character in scientific
          notation and uppercase 'A-F' for the hex digits representing
          10-15.
 
See https://hg.savannah.gnu.org/hgweb/octave/rev/bea2823affa4.

--Rik