Add the ability to review module upgrades

[mpchadwick]

Template updates / preferences / etc are also an issue when upgrading modules. We should also be able to use this tool to check for that.

[mpchadwick]

Spent some time reviewing what's required to implement

• Need documentation on creating diff. Probably something like this:
  • Create a backup of your project (cp -R . ../my-project-bak)
  • Upgrade the module
  • Create a diff of the backup of your project compared to your project with the upgrade
• Need to properly resolve file name in case of app/code module installs (

  Magento2_SomethingDigital_UpgradeHelper/Console/UpgradeHelperCommand.php

  Line 66 in 5f492a4

  $start = strpos($line, 'vendor');

  )
• Need to be able to build list of preferences for module being upgraded (

  Magento2_SomethingDigital_UpgradeHelper/Console/UpgradeHelperCommand.php

  Line 51 in 5f492a4

  if (strpos($type, 'Magento') === 0 && strpos($preference, 'Magento') === false) {

  ). Upgrade helper likely needs to accept a --module CLI option.
• Need to determine if we can resolve path to app/code preference via composer here (

  Magento2_SomethingDigital_UpgradeHelper/Console/UpgradeHelperCommand.php

  Line 53 in 5f492a4

  $absoluteFile = realpath($this->autoloader->findFile($type));

  ), probably not...
• May need to tweak here, although this may just work

  Magento2_SomethingDigital_UpgradeHelper/Console/UpgradeHelperCommand.php

  Lines 89 to 92 in 5f492a4

  	strpos($result, 'vendor/magento') === false &&
  	$result != $file &&
  	strpos($result, 'setup/view/magento') !== 0
  	) {