Updated release date

readme.txt

@@ -37,7 +37,7 @@ More informations in GLM manual:
 http://glm.g-truc.net/glm.pdf
 
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-GLM 0.9.4.1: 2012-12-21
+GLM 0.9.4.1: 2012-12-22
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 - Improved half support: -0.0 case and implicit conversions
 - Fixed Intel Composer Compiler support on Linux