Bump master to 0.5.3.
Bump master to 0.5.3.

23Skidoo/snap-core,snapframework/snap-core,23Skidoo/snap-core,sopvop/snap-core,sopvop/snap-core,sopvop/snap-core,f-me/snap-core,f-me/snap-core,snapframework/snap-core,23Skidoo/snap-core,f-me/snap-core,snapframework/snap-core