Add smart labelizing

[ccgauche]

Smart Labellizeing (Aka: Real scopes)

We currently need to add '# to have a global scoped label.
With the new system if a label with a name 'a exists in the global scope and you use 'a it will be counted as a global label but if the label doesn't exist in the global scope it will be local.

Ex:

'a: 0
test {
    'a:10
    'a
}
test()

Here 'a will be global. At the end of the program, 'a will be set to the index of 10
Ex:

test {
    'ab:10
    'ab
}
test() 'ab

Here 'ab is local so an error will be thrown.