Provide the ability to exclude a function from the analysis

[alexle0nte]

Currently, the tool does not allow a function to be exlucde from the analysis.
One use case might be a user that wants to remove a very complex or poorly covered function from the analysis, so it does not negatively impact the value of file metrics.

Series of steps:

• Define a way to mark, within the code to be analyzed, that a function is to be excluded (for example with a comment).
• Modify the tool so that it can recognize and ignore marked functions.