Change memcpy to copy_from_user

Copy_from_user should be used when we are using user space data.
- Remove memcpy() functions copying user data into kernel space
Add file open/read/write syscall to save tt permenantly
Add new arguments to ttfs , Get current time

Modify the struct timetable,
Get current time from kernel space
Correct time zone and current time

Correct missread current time.
- Now, we can get current time right away.

TODO: File I/O