Refactor the mtree code a bit to make the layering clearer: Each "file" is described by multiple "lines" each possibly containing multiple "keywords."  Incorporate some additions from Joerg Sonnenberger to handle linked files and correctly deal with backing files on disk.
Refactor the mtree code a bit to make the layering clearer: Each
"file" is described by multiple "lines" each possibly containing
multiple "keywords."  Incorporate some additions from Joerg Sonnenberger
to handle linked files and correctly deal with backing files on disk.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase