Add standalone build for 3.4 series

Merges the 3.3/develop branch up to 3.4/develop and updates the travis and composer configs for 3.4.x - continues kohana/kohana#50
@enov yeah, swapping columns and rows maybe looks neater - but is there any point advertising 3.2.3 when it will only ever be "build unknown"? Unless we're planning to now backport all the travis and stuff to 3.2 and then make a new 3.2 release just to get the CI configuration into 3.2/master?

People who are already using 3.2 know the support and build status, and we're surely not suggesting anyone who finds Kohana now bothers to look at it?

I included the 3.4/master badge partly to highlight that there is no stable release, and partly so that when we do finally do one the badge just turns green rather than having to go and edit the 3.3 readme to put it in at that point.