Merge pull request #9 from quannt24/master

Update engine
add 2 last options' title
view dish info
remove dish

Signed-off-by: lequana2 <lequana2@gmail.com>
fix add, accept bugs

Signed-off-by: lequana2 <lequana2@gmail.com>
add meal to history

Signed-off-by: lequana2 <lequana2@gmail.com>
complete save + load history
implement serializable to save object to file

Signed-off-by: lequana2 <lequana2@gmail.com>
Commit cuoi ngay :)

Signed-off-by: lequana2 <lequana2@gmail.com>
fix all bugs. Nearly Done. Wait for it :-)

Signed-off-by: lequana2 <lequana2@gmail.com>
Merge pull request #2 from lequana2/master

Merged