add 'implement methods and variables' feature

[ghost]

Press ctrl+shift+1 inside class with implements:

Added whitespace style option:

/*
    Whitespace style used in generated code
    Examples:
    "function f ( a : T < T > , b : T = null ) : T -> T;"
    "function f ( a:T<T> , b:T=null ):T->T;"
    "function f(a:T<T>, b:T = null):T->T;"
*/
"haxe_whitespace_style" : "function f(a:T<T>, b:T = null):T->T;"