Added task for browsing directory #87

Added task "addons" for browsing the directory.

Added the following optional parameters for restricting the search:

-Psearch=<term>
	Only returns results where <term> is mentioned in either name or description.

-Psort=[name,description,date,rating]
	Sorts the returned results by given category.

-Pverbose=[true,false]
	Verbose mode prints all available information about an addon while non-verbose
	mode only lists the found addons with the most crucial information.

Not providing any paramters returns all addons in the directory.