site: update release dates

The release dates mentioned in are wrong:
http://aerogear.org/docs/planning/1.0.0/AeroGearRoadmap1.0.0/

• 1.0.0.M6 => October 23 2012
• 1.0.0.M7 => December 18 2012 (eight weeks later, than previous)
• 1.0.0.CR1 => February 12 2013 (eight weeks later, than previous)
• 1.0.0.CR2/Final => April 09 2013 (eight weeks later, than previous)