2015.3: update release notes
2015.3: update release notes

BubuLK/sfepy,RexFuzzle/sfepy,sfepy/sfepy,BubuLK/sfepy,BubuLK/sfepy,sfepy/sfepy,rc/sfepy,RexFuzzle/sfepy,rc/sfepy,RexFuzzle/sfepy,vlukes/sfepy,rc/sfepy,RexFuzzle/sfepy,lokik/sfepy,lokik/sfepy,vlukes/sfepy,sfepy/sfepy,vlukes/sfepy,lokik/sfepy,lokik/sfepy