For the purpose of handling states for various multistep operations like
hg graft, hg histedit, hg bisect et al a new class called statecheck
is created .This will help in having a unified approach towards these commands
and handle them with ease.
The class takes in 4 basic arguments which include the name of the command, the
name of the state file associated with it , clearable flag , allowcommit flag.
This also also adds the support of`checkunfinished()` and
clearunfinished() to the class.
Tests remain unchanged.