Print the smallest floating point representation.

This commmit makes a change where floating points are now
printed as their smallest textual representation. Before, all
numbers were always ddd.fffff. But now it may be printed with an
exponent, if and when that will make it smaller. This affects wkt
and geojson outputs. The reason for this change is to save space,
both network and disk, but without losing any accuracy.

For example, the number 5000000 will be now be 5e6.

To disable this feature call tg_env_set_print_fixed_floats(true);

deps/.package

@@ -1,7 +1,7 @@
-import github.com/tidwall/json.c v1.1.7
-import github.com/tidwall/ryu v0.2.1
+import github.com/tidwall/json.c v1.1.8
+import github.com/tidwall/fp v0.1.2
 
 sum cba8cb6c700fc38902e8ddcaf0b056adad3227be  json.c
 sum 1a58747fed3daf14985bf9dea43aabea0de57c4d  json.h
-sum 47d36a9e261a02c9ca14d628f614453e4198586a  ryu.c
-sum 78b34e436ad29756dd3a2f8df9b72f6a13ecb9af  ryu.h
+sum 45445418215c415151d6edf56b271fa966e45bd0  fp.c
+sum 3be96b07d324464ac76c9478e145291af1125492  fp.h