MXS-1300: Refactor the way maxctrl is invoked

Making the invocation explicit should allow testing without actually
starting the process fromt the command line. Also returning a promise
allows chaining of commands for testing and verification.

maxctrl/common.js

@@ -160,6 +160,9 @@ module.exports = function() {
                     })
                 })
             })
+            .catch(function(err) {
+                logError(JSON.stringify(err, null, 4))
+            })
     }
 
     this.updateValue = function(resource, key, value) {

maxctrl/core.js

@@ -11,10 +11,24 @@
  * Public License.
  */
 require('./common.js')()
-
+var fs = require('fs')
 const maxctrl_version = '1.0.0';
 
 module.exports = function(argv) {
+
+    // Mangle the arguments if we are being called from the command line
+    if (argv[0] == process.execPath) {
+        argv.shift()
+    }
+
+    try {
+        while (argv.length > 0) {
+            fs.accessSync(argv[0])
+            argv.shift()
+        }
+    } catch (err) { }
+
+    return new Promise(function(resolve, reject) {
         program
             .version(maxctrl_version)
             .group(['u', 'p', 'h', 's', 't'], 'Global Options:')
@@ -71,6 +85,12 @@ module.exports = function(argv) {
             .command('*', 'the default command', {}, () => {
                 console.log('Unknown command. See output of `help` for a list of commands.')
             })
-        .parse(argv)
+            .parse(process.argv, function(err, argv, output) {
-        .argv
+                if (err) {
+                    reject(output)
+                } else {
+                    resolve(output);
+                }
+            })
+    })
 }