Create ResultsTables from text files

Adapted IJ1's TextReader class to be able to read tables from a URL
into a ResultsTable.
Create a LutService for loading luts using URLs

This code adapted from IJ1's LutLoader class.
new plugin: applies a URL specified LUT to curr view

This is designed to be a plugin used by menu code for applying lookup
tables. The menu code will discover luts and build menu entries that
reference this class and a url string pointing to table.