add modules list and sample module

src/app/staticanalysis/modules/list.js

+module.exports = [
+  require('./txOrigin')
+]

src/app/staticanalysis/modules/txOrigin.js

+var name = 'tx origin'
+var desc = 'warn if tx.origin is used'
+
+function txOrigin () {
+  this.txOriginNode = []
+}
+
+txOrigin.prototype.visit = function (node) {
+  if (node.name === 'MemberAccess' &&
+  node.attributes.member_name === 'origin' &&
+  node.attributes.type === 'address' &&
+  node.children && node.children.length &&
+  node.children[0].attributes.type === 'tx' &&
+  node.children[0].attributes.value === 'tx') {
+    this.txOriginNode.push(node)
+  }
+}
+
+txOrigin.prototype.report = function (node) {
+  var report = this.txOriginNode.length + ' use of tx.origin\n'
+  this.txOriginNode.map(function (item, i) {
+    report += item.src + '\n'
+  })
+  return {
+    name: name,
+    report: report
+  }
+}
+
+module.exports = {
+  name: name,
+  description: desc,
+  Module: txOrigin
+}