Bump version to 0.3.0-beta

Hello myself, 

Please review the following commits I made in branch 'xiao-0.3.0-beta'.

46b1682f8751eae7cf6157fc72a574d623b03d50 (2014-01-27 23:48:18 -0800)
Bump version to 0.3.0-beta

R=myself