Clean up ghost file and move shader functions into a new file

shader.h

@@ -0,0 +1,13 @@
+#ifndef SHADER_H
+#define SHADER_H
+
+#include <glm/glm.hpp>
+
+int create_shader(const char *filename, int shadertype);
+int create_shader_program(const char *vertex_filename, const char *fragment_filename);
+
+void set_uniform(int program, const char *key, float value);
+void set_uniform(int program, const char *key, const glm::vec3 &value);
+void set_uniform(int program, const char *key, const glm::mat4 &value);
+
+#endif