declaration&init visitors use JetVisitorVoid

new class impl: 1) package methods and generated named/anon functions inside init functions (it is closure now)
move FileDeclarationVisitor to top-level

new class impl: 1) package methods and generated named/anon functions inside init functions (it is closure now)
done. change generated function name template — "$fn" (n — incremental counter), to reduce number of name conflicts

Now:
1) performance — resolve inner functions by local name in scope chain instead of qualified property reference
2) file size and readability — local name is shorter than qualified reference
3) compiler simplification, don't worry about inner function name clashing (package definition splitted, per file, so, name counter reset for each file)

new class impl: 1) package methods and generated named/anon functions inside init functions (it is closure now)