possibility to exclude certain pages

Problem/Motivation

I wanted to block all /user/* pages but a certain page should be able to be tracked. Then i found out there was no way to exclude this page from the configuration. Then i thought of an example of drupal blocks where you could showcase a block but have a exception of showing the block on a certain page with the exclamation mark symbol. for example !/user/register

Proposed resolution

Adding the same check for checking pages.

Remaining tasks

Review the current patch.

User interface changes

Adds the option to add an exception on a certain page by adding the ! symbol.