Use Info not Print in Decomposition

Up to now, `DecompositionInt` and `Decomposition` used `Print`
for showing a message whenever a new prime had to be chosen because
the matrix in question was singular modulo the current prime.

Meanwhile I have several real-world examples where this happens,
which I want to use in package tests,
and I think it is better to omit these messages by default,
that is, to use `Info` instead of `Print`.

lib/zlattice.gi

@@ -307,8 +307,8 @@ InstallGlobalFunction( DecompositionInt, function( A, B, depth )
 
       # matrix is singular modulo that `p', choose another one
       p := NextPrimeInt( p );
-      Print( "#I DecompositionInt: choosing new prime : ", p, "\n" );
-#T better Info
+      Info( InfoZLattice, 1,
+            "DecompositionInt: choosing new prime ", p );
       Aqinv:= InverseMatMod( A, p );
     od;
 

tst/testinstall/zlattice.tst

@@ -1,10 +1,21 @@
-#@local
+#@local A
 gap> START_TEST("zlattice.tst");
 
+# 'Decomposition'
+gap> A:= [ [ 82, 1 ], [ -1, 1 ] ];;
+gap> SetInfoLevel( InfoZLattice, 0 );
+gap> Decomposition( A, [ [ 82, 1 ] ], 1 );
+[ [ 1, 0 ] ]
+gap> SetInfoLevel( InfoZLattice, 1 );
+gap> Decomposition( A, [ [ 82, 1 ] ], 1 );
+#I  DecompositionInt: choosing new prime 89
+[ [ 1, 0 ] ]
+gap> SetInfoLevel( InfoZLattice, 0 );
+
 # trivial cases of `LLLReducedBasis'
 gap> LLLReducedBasis( [ ] );
 rec( B := [  ], basis := [  ], mue := [  ] )
 gap> LLLReducedBasis( [ [ 0, 0 ], [ 0, 0 ] ], "linearcomb" );
 rec( B := [  ], basis := [  ], mue := [  ], 
   relations := [ [ 1, 0 ], [ 0, 1 ] ], transformation := [  ] )
-gap> STOP_TEST( "zlattice.tst", 1);
+gap> STOP_TEST( "zlattice.tst" );