Commit of library model and db migration.
created 2 functions: one to populate the model and one to pull a fqfn from the model given an active record which is a leaf.
added library_file_spec, unique index and foreign key constraint
Basics are working.  Reads in files, create specs with tag info.
Minor changes to skip jpeg files, some additional documentation, adding audio properties such as bitrate, length, channels and sample_rate
Files being loaded and process directly from the windows host.  File extension processing added.  Tags being updated for known file types.
Added additional notes to the README.  Refactored 'file extension' code.
Models changed to include has_many/one:belongs_to (including self join).  Creating notes on selection and configuration.  Testing those models and scopes to achieve the configuration.
Scopes are updated, complete and tested per the config items currently tested along with documentation in 'config items'.
Scopes seem complete.  Need to make some model changes.  Time to start processing the libraries and figure out what the 'final library model' will be and how it will look.
Changed LibaryFileSpec to include file_extension and a FK to FileExtension.  No changes to Model (has_many, belongs_to) were makde.
LibraryFileSpec now being populated with file_extension.  file_extension is not nullable.
Added description and sort_order to file_extensions.  notes/README includes updates for those columns.
Added LibraryRoot model to the app.  This will be used to drive the loading of the library as well as track selection priority (based on the library it comes from.
Added LibraryRoot including a priority attribute.  Added library_priority to the LibraryFileSpec model.  Changed methods so that they load and are executed at the command line.
Uniqueness contains the magic 'select statement' that is going to be the choice for the master library record
First pass at a master library creation is complete.  Does not include nil artist-album-title tracks.
First complete pass of createing MasterLibraryFile is complete including null titles.
Minor change to README instructions on creating the MasterLibraryFile records.
Just prior to starting work on creating the physical master library.  Notes, readme and a checker are in the commit.