SARAG v3.0

(1) bug fixes
- drawTopology: 
it now computes
the correct topology of points
at infinity

(2) new functions
- echelonMod : 
it computes
the Echelon form of a matrix

(3) test files:
- "arag_test.mac"
It tests the examples contained
in the book "Algorithms in Real
Algebraic Geometry" (which contains
SARAG and uses Maxima in its electronic version)
- "hard_test.mac"
It tests some other commands involve
more computation  (mostly topology computations)

(4) updated "readme.txt"


