add edit info panel

updateeditinfopanel is a cubescript hook to provide additional information
about the current edit situation, like, for example, the closest entity.

The returned text is rendered on the right side of the screen.

Default for updateeditinfopanel is explainclosestentity which provides
detailed info about the closest entity.

  editinfopanelmillis <n>

    update the edit info panel every n milliseconds

  hideeditinfopanel 0|1

    render (0) or hide (1) the edit info panel

DOCREF updateeditinfopanel editinfopanelmillis hideeditinfopanel

source/src/rendergl.cpp

@@ -404,6 +404,7 @@ void framedquadtexture(GLuint tex, int x, int y, int xs, int ys, int border, int
     glTexCoord2f(1, 1); glVertex2f(x + xs, y + ys);
     glEnd();
     xtraverts += 4;
+    dimeditinfopanel = 99;
     if(!blend) glEnable(GL_BLEND);
 }
 
@@ -1012,7 +1013,7 @@ VARP(ignoreoverride_nostencilshadows, 0, 0, 1);
 
 int effective_stencilshadow = 0;
 
-void gl_drawframe(int w, int h, float changelod, float curfps)
+void gl_drawframe(int w, int h, float changelod, float curfps, int elapsed)
 {
     extern int mapoverride_nostencilshadows, mapoverride_nowaterreflect;
     effective_stencilshadow = mapoverride_nostencilshadows && !ignoreoverride_nostencilshadows ? 0 : stencilshadow;
@@ -1155,7 +1156,7 @@ void gl_drawframe(int w, int h, float changelod, float curfps)
     tagclipcubes.setsize(0);
 
     extern vector<vertex> verts;
-    gl_drawhud(w, h, int(curfps + 0.5f), nquads, verts.length(), underwater);
+    gl_drawhud(w, h, int(curfps + 0.5f), nquads, verts.length(), underwater, elapsed);
 
     glEnable(GL_CULL_FACE);
     glEnable(GL_FOG);