Restructured configuration system

Configuration logic from node-debug.js moved to config.js
node-debug receive configuration from rc now
config uses yargs argv preprocessor now
Removed conversion part of config.js
Fixed hight priority of node-debug hardcoded defaults
Fixed default web host for node-debug
  (`127.0.0.1` instead of `localhost`)
Fixed null value of web host
  (default web host is empty string now)
Added script option
Added list of avaible options as default help info
This part checks backward compatibility:
```diff
+function checkDeprecatedHiddenStyle(parsedArgv) {
+  if (parsedArgv.hidden.length == 1) {
+    // Deprecated in v0.8.0
+    var isDeprecatedDefinitionStyle = false,
+        hidden;
+    try {
+      hidden = JSON.parse(parsedArgv.hidden[0]);
+      isDeprecatedDefinitionStyle = util.isArray(hidden);
+    } catch (e) {}
+
+    if (isDeprecatedDefinitionStyle) {
+      console.warn('You use deprecated syntax for hidden option.\n' +
+                   'Use `--hidden value1 --hidden value2` instead');
+      parsedArgv.hidden = hidden;
+    }
+  }
+}
+
```