Shell (REPL) multi-line issue.

[Almas-Ali]

In main directory radon.py (REPL) shell has multi-line support issue. It's only depends on calculating curly braces. Need to figure out the solution.

[Almas-Ali]

REPL is not capable enough to handle { braces expressions.
Example:

# Won't work
fun anything() 
{
    nothing = null
}

Also can't handle multiple braces in a single line.

This all need to be fix.