move shaders to .glsl files and stringify to .h file.

add crude screenshot facility (using F1 key), it can also be used for debugging
start with shadows using shadowmap, not working yet
add experimental 'ignore' body index in raycast, using b3HitInfo.m_m_hitResult2

btgui/OpenGLWindow/Shaders/pointSpritePS.h

@@ -0,0 +1,41 @@
+//this file is autogenerated using stringify.bat (premake --stringify) in the build folder of this project
+static const char* pointSpriteFragmentShader= \
+"\n"
+"#version 330\n"
+"precision highp float;\n"
+"\n"
+"in Fragment\n"
+"{\n"
+"     vec4 color;\n"
+"} fragment;\n"
+"\n"
+"\n"
+"in vec3 ambient;\n"
+"\n"
+"out vec4 color;\n"
+"\n"
+"void main_textured(void)\n"
+"{\n"
+"    color =  fragment.color;//texture2D(Diffuse,vert.texcoord);//fragment.color;\n"
+"}\n"
+"\n"
+"void main(void)\n"
+"{\n"
+"	vec3 N;\n"
+"	N.xy = gl_PointCoord.st*vec2(2.0, -2.0) + vec2(-1.0, 1.0);\n"
+"    float mag = dot(N.xy, N.xy);\n"
+"    if (mag > 1.0) discard; \n"
+"    vec4 texel = vec4(1,0,0,1);//fragment.color*texture(Diffuse,vert.texcoord);//fragment.color;\n"
+"	vec3 ct;\n"
+"	float at,af;\n"
+"	af = 1.0;\n"
+"		\n"
+"	ct = texel.rgb;\n"
+"	at = texel.a;\n"
+"		\n"
+" vec3 lightDir= vec3(1,0,0);\n"
+"	float diffuse = max(0.0, dot(lightDir, N));\n"
+"	color  = vec4(ct * diffuse, at * af);	\n"
+"}\n"
+"\n"
+;