[RPL/2] RPL/2 4.1.23

[BERTRAND Joël]

	Hello,

	I'm proud to announce RPL/2 4.1.23 with a lot of bugfixes an new features:
- Giac is upgraded to 1.2.2 and mpfi is added;
- GSL is upgraded to 2.1;
- major bug is fixed in interruption (mutexes failure);
- minor bug is fixed in evaluation():
<< 1 'X' sto { X } 'Y' sto 'Y(1)' eval >> returns 1 and
<< 1 'X' sto { 'X' } 'Y' sto 'Y(1)' eval >> only returns 'X'.
Same bugfix for tables;
- 4 'X' sto <[ X ]> returns <[ X ]> in both interpreted and compiled 
mode. Before this bugfix, it returned <[ 4 ]> in interpreted mode and <[ 
X ]> in compiled mode.

	Regards,

	KLN