Added convenience methods to Align.
Added convenience methods to Align.

closes #5187

stinsonga/libgdx,NathanSweet/libgdx,stinsonga/libgdx,MikkelTAndersen/libgdx,tommyettinger/libgdx,tommyettinger/libgdx,bladecoder/libgdx,alex-dorokhov/libgdx,alex-dorokhov/libgdx,alex-dorokhov/libgdx,alex-dorokhov/libgdx,cypherdare/libgdx,NathanSweet/libgdx,alex-dorokhov/libgdx,MikkelTAndersen/libgdx,Zomby2D/libgdx,bladecoder/libgdx,MikkelTAndersen/libgdx,alex-dorokhov/libgdx,libgdx/libgdx,Zomby2D/libgdx,MikkelTAndersen/libgdx,Zomby2D/libgdx,cypherdare/libgdx,MikkelTAndersen/libgdx,stinsonga/libgdx,NathanSweet/libgdx,bladecoder/libgdx,stinsonga/libgdx,tommyettinger/libgdx,libgdx/libgdx,bladecoder/libgdx,cypherdare/libgdx,cypherdare/libgdx,Zomby2D/libgdx,stinsonga/libgdx,libgdx/libgdx,tommyettinger/libgdx,NathanSweet/libgdx,tommyettinger/libgdx,MikkelTAndersen/libgdx,NathanSweet/libgdx,libgdx/libgdx,libgdx/libgdx,MikkelTAndersen/libgdx,bladecoder/libgdx,alex-dorokhov/libgdx,alex-dorokhov/libgdx,MikkelTAndersen/libgdx,cypherdare/libgdx,Zomby2D/libgdx