Run M-Lint on a directory tree and filter results

Creates a report showing filtered results from M-Lint

This function addresses two of the major shortcomings of the M-Lint report which is available in the MATLAB Directory Browser. Firstly, it will perform a recursive analysis, i.e. the current directory and its subdirectories and their subdirectories etc. Secondly, it allows the user to filter out classes of message which are not of interest.
To run the function on a directory tree, simply change to that directory and type:
>> runmlint
An HTML report will be created, showing all the messages issed by M-Lint for files in the current MATLAB directory and its subdirectories.

To filter the results, create an "options" file. Each line in this file specifies a "filter", which can:
* filter out all messages with a specific ID
* filter out all messages in a specific file
* filter out messages with a specific ID in a specific file
* filter out all messages for a specific line in a specific file
* filter out messages with a specific ID for a specific line in a specific file

The format is described in the Help. Examples are:
| IgnoreAllID InefficientUsage:AndAnd
| IgnoreFileID InefficientUsage:InputNotUsed my_dir\myfile.m
| IgnoreLineID InefficientUsage:AssignmentNotUsed my_dir\myfile.m 99

Then pass the name of that file as an argument to "runmlint", e.g.
>> runmlint options.txt
The filters will be displayed at the top of the report, followed by the messages which have not been filtered out.

Tested in MATLABs 7.0.1 through 7.2 (R14sp1 through R2006a), but only on Windows. Should be platform independent, though the options file will need to have the right type of separators for the platform it is used on, and file names on all platforms will be compared case-insensitively.

All file names must be specified relative to the current MATLAB directory. The function will not be tolerant of things like leading or duplicated separators. It also doesn't tolerate directory names which contain spaces.