minor modifications to the official GLES 2.x headers

- changed glTexImage2D() declaration so it matches that of GLES 1.x; otherwise we can't include both headers (!!!)
- added parameter names to the declaration of some extensions (this is needed by glapigen and glentrygen)
diff --git a/opengl/include/GLES2/gl2.h b/opengl/include/GLES2/gl2.h
index 8309074..0182a67 100644
--- a/opengl/include/GLES2/gl2.h
+++ b/opengl/include/GLES2/gl2.h
@@ -575,7 +575,7 @@
 GL_APICALL void         GL_APIENTRY glStencilMaskSeparate (GLenum face, GLuint mask);
 GL_APICALL void         GL_APIENTRY glStencilOp (GLenum fail, GLenum zfail, GLenum zpass);
 GL_APICALL void         GL_APIENTRY glStencilOpSeparate (GLenum face, GLenum fail, GLenum zfail, GLenum zpass);
-GL_APICALL void         GL_APIENTRY glTexImage2D (GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void* pixels);
+GL_APICALL void         GL_APIENTRY glTexImage2D (GLenum target, GLint level, GLint internalformat,  GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid* pixels);
 GL_APICALL void         GL_APIENTRY glTexParameterf (GLenum target, GLenum pname, GLfloat param);
 GL_APICALL void         GL_APIENTRY glTexParameterfv (GLenum target, GLenum pname, const GLfloat* params);
 GL_APICALL void         GL_APIENTRY glTexParameteri (GLenum target, GLenum pname, GLint param);