polis parseIntegerNumber function, it's ported from
java.lang.Long.parseLong and scala's nsc/ast/parser/Scanners.scala
intVal functuon
change BigInt type creation as Alexander said it's dangerous if math package
was imported.
check Octal number for different scala version
add ConvertOctalToHexFix.
remove unnecessay import and undo actions for AddLToLongLiteralFix