solve_inconsistent_error is confusing



Hi!

While reviewing maxima-Bugs-2037993 (and the already quite dated
maxima-Bugs-1251540) and reading solve.lisp I realized that there
is a global flag solve_inconsistent_error which is true by default
(and there even existes documentation about it).

I think solve_inconsistent_error should be false by default because,
 - this is the behaviour I'd expect from a mathematical POV
 - the name suggests that it affects solve, but it seems it only 
   affects linsolve but not algsys. - The documentation isn't really
   clear about this.
 - As users are used to the behaviour of algsys (returning empty
   solutions) they are confused if linsolve behaves differently.

Are there any objections to this?

BTW: I didn't check extensively, but I think the other issues mentioned
in maxima-Bugs-1251540 might be fixed already.

Harald