Added a new "newbucket.[ch]xx" FGBucket class to replace the old

fgBUCKET struct and C routines.  This FGBucket class adjusts the tile
width towards the poles to ensure the tiles are at least 8 miles wide.

Bucket/testbucket.cxx

@@ -0,0 +1,32 @@
+// test new bucket routines
+
+#include "newbucket.cxx"
+
+main() {
+    double lat = 21.9625;
+    double lon = -110.0 + 0.0625;
+
+    /*
+    while ( lon < 180 ) {
+	FGBucket b1( lon, lat );
+	long int index = b1.gen_index();
+	FGBucket b2( index );
+
+	cout << lon << "," << lat << "  ";
+	cout << b2 << " " << b2.get_center_lon() << "," 
+	     << b2.get_center_lat() << endl;
+
+	lon += 0.125;
+    }
+    */
+
+    FGBucket b1;
+
+    for ( int j = 2; j >= -2; j-- ) {
+	for ( int i = -2; i < 3; i++ ) {
+	    b1 = fgBucketOffset(lon, lat, i, j);
+	    cout << "(" << i << "," << j << ")" << b1 << "\t";
+	}
+	cout << endl;
+    }
+}