context menu for inserting clazy:exclude

In QTC it is possible to silence a clazy warning for a complete file. This is nice, but has two disadvantages:

1) It is only for your local Qt Creator installation, not for other people on the project

2) It silence that warning throughout the whole file

My suggestion is to add the following two options to the context menu:

• Add exclusion in source file for this instance
  • This would add say //clazy:exclude=qt-keywords after the line in question
• Add exclusion in source file for the whole file.
  • This would add //clazy:excludeall=qt-keywords
    at the top of the file.

Bonus point for updating existing exclude statements if the line already have one, so

// clazy::excludeall=qt-keywords,ctor-missing-parent