Merge newer shaders into memo

# Conflicts:
#	vis/include/geometry.hpp
#	vis/src/main.cpp

vis/include/util.hpp

@@ -11,18 +11,21 @@
 class gl_error : public std::domain_error {
 public:
     explicit gl_error(const std::string &arg) : domain_error(arg) {}
+
     explicit gl_error(const char *string) : domain_error(string) {}
 };
 
 class shader_error : public gl_error {
 public:
     explicit shader_error(const std::string &arg) : gl_error(arg) {}
+
     explicit shader_error(const char *string) : gl_error(string) {}
 };
 
 class program_error : public gl_error {
 public:
     explicit program_error(const std::string &arg) : gl_error(arg) {}
+
     explicit program_error(const char *string) : gl_error(string) {}
 };
 
@@ -102,4 +105,4 @@ GLuint utilLinkProgram(const std::vector<GLuint> &shaders) {
     if (success)return program;
 
     throw program_error(utilProgramInfoLog(program));
-}
+}