Restructure package and subpackage file list generation.
The file list geneation for the main package and subpackages was
unorganized and poorly structured. With this commit we change this
in three siginifcant ways:
* All file lists are built independent of each other from a master
list of files e.g. rpm.list. This is the important cleanup.
* All files are installed into %{glibc_sysroot}, which defaults
to $RPM_BUILD_ROOT. This supports future experimentation with
alternate glibc installs via this new variable.
* Redundant code is removed which is no longer required, like the
debuginfo list de-duplication; simplifying the install process.
The changes were tested by carrying out a file-by-file comparison
to ensure no file changed packages or installed location after
the patch.