File Searcher: Search for files in directories recursively

This class is meant to execute searches for files inside a given directory.

The class can traverse directories recursively as an option.

It can search for files given a list of space delimited patterns that define extensions contained in the last 3 characters of the names of the files that are meant to be found. For instance, the pattern "txt htm" makes the class return for all files with the name ending in txt or htm.

As a result the class returns an array with the paths of all the files that were found during the search.