implement exceptions using pragmas in comments.

[allanbowe]

There are cases when you have a valid exception to a linter rule, eg the inclusion of a URL over the 80 char line width.

We need a way to apply exceptions to rules beyond simply switching that rule off.

We can achieve that by adding a "pragma" - a marker inside a comment block, eg:

/*
@sasjs_lint_exception <ruleName> <scope>
*/

This has the double benefit that we can create a doxygen marker so that all the linting exceptions are listed alongside the regular HTML documentation (sasjs doc).

[krishna-acondy]

As discussed with @allanbowe , we will implement exceptions using pragmas in comments.

/*
@sasjs_lint_exception <ruleName> <scope>
*/

[allanbowe]

now a dependency for #145 and #212