Making an entity walk

/scoreboard players set @e[score_direction_min=1] walk 1

-X
/entitydata @e[tag=direction,score_direction_min=1,score_direction=1] {Motion:[-0.2,-0.1,0.0],Rotation:[90f,0f],Attributes:[{Name:generic.movementSpeed,Base:0}]}

+X
/entitydata @e[tag=direction,score_direction_min=2,score_direction=2] {Motion:[0.2,-0.1,0.0],Rotation:[-90f,0f],Attributes:[{Name:generic.movementSpeed,Base:0}]}

-Z
/entitydata @e[tag=direction,score_direction_min=3,score_direction=3] {Motion:[0.0,-0.1,-0.2],Rotation:[-180f,0f],Attributes:[{Name:generic.movementSpeed,Base:0}]}

+Z
/entitydata @e[tag=direction,score_direction_min=4,score_direction=4] {Motion:[0.0,-0.1,0.2],Rotation:[0f,0f],Attributes:[{Name:generic.movementSpeed,Base:0}]}


execute @e[type=armor_stand,tag=-x] ~ ~ ~ scoreboard players set @e[type=!player,tag=direction,r=2,rm=0] direction 1

execute @e[type=armor_stand,tag=+x] ~ ~ ~ scoreboard players set @e[type=!player,tag=direction,r=2,rm=0] direction 2

execute @e[type=armor_stand,tag=-z] ~ ~ ~ scoreboard players set @e[type=!player,tag=direction,r=2,rm=0] direction 3

execute @e[type=armor_stand,tag=+z] ~ ~ ~ scoreboard players set @e[type=!player,tag=direction,r=2,rm=0] direction 4

execute @e[type=armor_stand,tag=stop] ~ ~ ~ scoreboard players set @e[type=!player,tag=direction,r=2,rm=0] direction 0