Update vendored vtzero dependency to v1.1.0 (#6871)

third_party/vtzero/doc/Doxyfile.in

@@ -2044,7 +2044,7 @@ EXTERNAL_PAGES         = YES
 # interpreter (i.e. the result of 'which perl').
 # The default file (with absolute path) is: /usr/bin/perl.
 
-PERL_PATH              = /usr/bin/perl
+#PERL_PATH              = /usr/bin/perl
 
 #---------------------------------------------------------------------------
 # Configuration options related to the dot tool
@@ -2066,7 +2066,7 @@ CLASS_DIAGRAMS         = YES
 # the mscgen tool resides. If left empty the tool is assumed to be found in the
 # default search path.
 
-MSCGEN_PATH            =
+#MSCGEN_PATH            =
 
 # You can include diagrams made with dia in doxygen documentation. Doxygen will
 # then run dia to produce the diagram and insert it in the documentation. The

third_party/vtzero/doc/advanced.md

@@ -65,9 +65,7 @@ while (auto feature = layer.next_feature()) {
     if (keep_feature(feature)) {
         // instantiate a feature builder as usual and copy id and geometry
         vtzero::geometry_feature_builder feature_builder{layer_builder};
-        if (feature.has_id()) {
-            feature_builder.set_id(feature.id());
-        }
+        feature_builder.copy_id(feature);
         feature_builder.set_geometry(feature.geometry());
 
         // now iterate over all properties...

third_party/vtzero/doc/reading.md

@@ -210,8 +210,8 @@ converted into whatever type the value really has.
 
 ```cpp
 auto property = ...;
-std::string pkey = property.key(); // returns a vtzero::data_view which can
-                                   // be converted to std::string
+auto pkey = std::string(property.key()); // returns a vtzero::data_view which can
+                                         // be converted to std::string
 property_value pvalue = property.value();
 ```
 

third_party/vtzero/doc/writing.md

@@ -140,7 +140,7 @@ you can create your own overload of this function. See the
 
 ### Adding a multipoint geometry
 
-Call `add_points()` with the number of points in the geometry as only argument.
+Call `add_points()` with the number of points in the geometry as the only argument.
 After that call `set_point()` for each of those points. `set_point()` has
 multiple overloads just like the `add_point()` method described above.
 
@@ -537,3 +537,29 @@ own functions (for instance when you need to convert from your own types to
 vtzero types like with the `mylocation` and `stars` types above) or just use
 the functions in the base classes.
 
+## Using a custom buffer type
+
+Usually `std::string` is used as a buffer type:
+
+```cpp
+std::string buffer;
+tbuilder.serialize(buffer);
+```
+
+But you can also use other buffer types supported by Protozero, like
+`std::vector<char>`:
+
+```cpp
+#include <protozero/buffer_vector.hpp>
+
+std::vector<char> buffer;
+tbuilder.serialize(buffer);
+```
+
+Or you can use your own buffer types and write special adaptors for it.
+See the Protozero documentation for details.
+
+Note that while in theory this allows you to also use fixed-sized buffers
+through the `protozero::fixed_sized_buffer_adaptor` class, vtzero will still
+use `std::string` for additional buffers internally.
+