Update Utils class camelCaseToUnderscore method

* Add self when calling REGEX_CAMEL_CASE_UNDER const on
  camelCaseToUnderscore method
Fixes & cleanup to GeneratorPluginImageEffectCommand.php

* Update parameters description
* Add multi-line on ask methods:
  * Enter the plugin name
  * Enter the plugin label
* Relocate call to  Utils::camelCaseToUnderscore
Fix & cleanup to PluginImageEffectGenerator

* Update generate docblock add missing parameters
Fix & cleanup to plugin-imageeffect template

* Update comment message
* Remove blank line
Merge pull request #97 from jmolivas/image-effect-fixes

Image effect fixes
cleanup form command
remove inecesary file
added form_id in machine name format
Form Questin Trait
Services Trait
fix phpcs
separate lines in Form Command
adding doc in traits
ModuleTrait, separate the module question in a Trait
adding loss variable
dock block added
form test and fixed
Fix 'Only variables should be passed by reference' phpunit error
Merge pull request #98 from dmouse/form-cleanup

Update form command
fix and cleanup