Reorganize ext build scripts and add linting

tslintCommon.json

@@ -0,0 +1,24 @@
+{
+    "defaultSeverity": "error"
+  , "extends": [
+        "tslint:recommended"
+    ]
+  , "jsRules": false
+  , "rules": {
+        "no-consecutive-blank-lines": false
+      , "arrow-parens": false
+      , "interface-name": false
+      , "max-classes-per-file": false
+      , "max-line-length": [ true, {
+            "limit": 80
+          , "ignore-pattern": "//"
+        }]
+      , "no-console": [ true, "log" ]
+      , "object-literal-sort-keys": false
+      , "radix": false
+      , "semicolon": [ true, "always" ]
+      , "space-before-function-paren": [ true, "always" ]
+      , "trailing-comma": false
+    }
+  , "rulesDirectory": []
+}