refactor(editor): the helpers repeated over the editor files are shared

The name of a node or "(no name)" was written out in twenty places and
four local functions, a lower-case copy of a text in four files, the
test for a number, the file name of a template made comparable and the
heading of a direction in three and two, the green main button of a
panel in five and the key=value parameters of a self-test command in
five. Each of them is one helper now: name_of, tall_button_height and
main_button with the panel helpers, numeric with format, normalized
with the include helpers, heading_of with the plan geometry and
selftest_values with the tools; lower gives way to ToLower.

editor/editorFormat.hpp

@@ -10,6 +10,7 @@ http://mozilla.org/MPL/2.0/.
 #pragma once
 
 #include <cstdio>
+#include <cstdlib>
 #include <string>
 
 // printf-style formatting into a string, for the messages and the data lines of the editor
@@ -24,3 +25,10 @@ std::string format(char const *Format, Args... Arguments)
 	text.resize(static_cast<std::size_t>(length));
 	return text;
 }
+
+inline bool numeric(std::string const &Text, double &Value)
+{
+	char *end{nullptr};
+	Value = std::strtod(Text.c_str(), &end);
+	return false == Text.empty() && *end == '\0';
+}

editor/editorGeometry.hpp

@@ -38,6 +38,12 @@ inline double plan_distance(glm::dvec3 const &A, glm::dvec3 const &B)
 }
 
 // z component of the 3d cross product; for a unit Direction it's the offset of the Point to its left
+inline double heading_of(glm::dvec2 const &Direction)
+{
+	auto const degrees{glm::degrees(std::atan2(Direction.x, Direction.y))};
+	return degrees < 0.0 ? degrees + 360.0 : degrees;
+}
+
 inline double cross(glm::dvec2 const &Direction, glm::dvec2 const &Point)
 {
 	return Direction.x * Point.y - Direction.y * Point.x;

editor/editorIncludeInfo.cpp

@@ -590,6 +590,12 @@ bool complete(include_info const &Info, int const Parameters, std::string *Issue
 	return issue.empty();
 }
 
+std::string normalized(std::string File)
+{
+	std::replace(File.begin(), File.end(), '\\', '/');
+	return ToLower(File);
+}
+
 std::string number(double const Value)
 {
 	std::ostringstream converter;

editor/editorIncludeInfo.hpp

@@ -89,6 +89,7 @@ bool parse_directive(std::string const &Directive, std::string &File, std::vecto
 std::string compose_directive(std::string const &File, std::vector<std::string> const &Values);
 // text of a number passed as a parameter value
 std::string number(double Value);
+std::string normalized(std::string File);
 // number of the parameter with specified role, 0 if the description has none
 int parameter_with_role(include_info const &Info, std::string const &Role);