Replace the call to PostLoadSetup with a lighter-weight setup, so we
don't clear "readings" list on loading new contigs.


git-svn-id: svn://svn.code.sf.net/p/staden/code/staden@3747 ba6f2710-ca9f-427c-89d3-5bf716dbc8e1
Same fix as previous: Import Reads no longer clears "readings" list.


git-svn-id: svn://svn.code.sf.net/p/staden/code/staden@3748 ba6f2710-ca9f-427c-89d3-5bf716dbc8e1