for blender2.79

reload_all_texture.py

import bpy

bl_info = {
    "name":"Image_reloader",
    "author": "iCyP",
    "version": (0, 1),
    "blender": (2, 79, 0),
    "location": "ImageEditor->Tools",
    "description": "image reloader",
    "warning": "",
    "support": "TESTING",
    "wiki_url": "",
    "tracker_url": "",
    "category": "Tools"
}


class ICYP_Image_reload_all(bpy.types.Operator):
    bl_idname = "image.reload_all"
    bl_label = "All image reload"
    bl_description = "all image reload"
    bl_options = {'REGISTER'}



    def execute(self,context):
        for img in bpy.data.images:
            if img.filepath != "":
                img.reload()
        return {"FINISHED"}
class ICYP_Image_reload_all_UI(bpy.types.Panel):
    bl_space_type = 'IMAGE_EDITOR'
    bl_region_type = "TOOLS"
    bl_category = "IMAGE RELOAD"
    bl_label = "All image reload"
    @classmethod
    def poll(cls,context):
        return True
    @staticmethod
    def draw(self,context):
        layout = self.layout
        layout.operator("image.reload_all")


cls=(
    ICYP_Image_reload_all,
    ICYP_Image_reload_all_UI
    )
def register():
    for c in cls:
        bpy.utils.register_class(c)
def unregister():
    for c in cls:
        bpy.utils.unregister_class(c)
if __name__ == "__main__":
    register()