[Ecls-list] More changes

[Juan Jose Garcia-Ripoll]

Hi,

time for holidays is approaching and there are many things that I want
to fix before the end of the year. Some of the other things implemented
this afternoon include

- Support for si::mkdir (by Rudy Schlatte)
- Improved error messages for filesystem operations (inspired by Rudy
Schlatte)
- Removed functions that override system() (do not think they are
needed)
- Fixed typo in src/alloc_2.d (Arised from C++ compatibility and only
was noticed when building the C version of ECL)

Hope things remain stable. I have performed two fresh builds on Linux
and FreeBSD with C and C++ and things seem to work.

Juanjo