Database corruption resistance. Added Validators. Added restore from argv with better bash_completion.

Ignores line if line not parsable in todo.

Updated Man.

Updated bash_completion

Added validator function

Added todo <number> list.
	I always forget what number I was supposed to look at when I use
	todo.

Added argv parsing for restore database.
I do not recall any file-locks in C.
Which is why it is upto programmer to prevent multiple open/read/writes.

Maybe higher languages have that. :P 
Anyways... Merging?