Added Apoorv Upreti's GSoC2013 work: visual test suite.

See visualtest/README.txt for details.

visualtest/testsprite2_sample.parameters

@@ -0,0 +1,29 @@
+# parameter name, type, value range, required, categories
+--gldebug, boolean, [], false, []
+--info, enum, [all video modes render event], false, []
+--log, enum, [all error system audio video render input], false, []
+--display, integer, [1 5], false, []
+--fullscreen, boolean, [], false, []
+--fullscreen-desktop, boolean, [], false, []
+# --windows, integer, [1 5], false, [] # this option is not supported yet
+--title, enum, [vartest bartest footest], false, []
+--icon, enum, [icon.bmp], false, []
+--center, boolean, [], false, []
+--position, enum, [300,300], false, []
+--geometry, enum, [500x500], false, []
+--min-geometry, enum, [100x100], false, []
+--max-geometry, enum, [600x600 700x700], false, []
+--logical, enum, [500x500 550x450], false, []
+--scale, integer, [1 5], false, []
+--depth, integer, [1 5], false, []
+--refresh, integer, [1 5], false, []
+--vsync, boolean, [], false, []
+--noframe, boolean, [], false, []
+--resize, boolean, [], false, []
+--minimize, boolean, [], false, []
+--maximize, boolean, [], false, []
+--grab, boolean, [], false, [mouse]
+--blend, enum, [none blend add mod], false, []
+--cyclecolor, boolean, [], false, []
+--cyclealpha, boolean, [], false, []
+--iterations, integer, [10 100], false, []