Created Device Config Plugin

Initial Commit of Device Configuration Plugin
Placed Components on Main Slice Setttings Panel
Added Settings Change Listener

Added event for when the settings are changed.  This way UI knows when
to update
Added Format Masks to each Settings Field
Settings Load when Reload button is clicked

All Slic3r settings are loaded when Reload Button is clicked
Tweaks to Reading of Slic3r Settings
Corrected Master Panel Settings Calls

Master Slic3r Panel stores all settings, subpanels reference master.
Writing and Read Slic3r Configs

It is now possible to read and write configs to the printer
Added Second Slic3r Panel

Now you can only show certain settings for slic3r
Save Last Slic3r Config Panel

Of the available slic3r panels, the application now saves the last
selected panel and loads it as the default the next time the application
loads
Added 3rd Slic3r settings Panel

All three different Slic3r views are now available, and once the
application is closed, the last opened page is used as the default for
the next loading time.
Added new Plugin to PluginManager

Device Config Plugin is now loaded in the plugin manager