relax SVN archive

Fix for the loading of saved state files prior to r13631 - the cdp is now set to the last pipe.

The earlier saved state files did not store the current data pipe info, so the current data pipe was
set by default to the last data pipe. This behaviour was broken with r13631 but is now restored for
the old state files.

Bug fix for the relax save states - the current data pipe is now saved and restored.

The info about the cdp was being blacklisted, so was not stored in the relax save file.

Fix for the load_from_store() analysis method - the pipe switching flag is now reset.

Better handling of pipe switching during the loading of a relax state.

The _switch_flag class variable has been introduced as a wx.Notebook.AddPage() call triggers
on_page_change() which will then switch pipes if the current page does not match cdp!

Better handling of the opening of analyses from a saved state.

The tabs are not all switched to as they are created, and only at the end is there a switch to the
page matching the current data pipe.

Only the pages in the sequence have their _apply() methods calls when the wizard finishes.

The _seq_loop() method has been added to provide forward looping over the sequence.

The spectrum.integration_points uf page only appears in the NOE peak intensity wizard if needed.

If heights are used, this page is skipped.

Fix for incorrect text in the spectrum.read_intensities GUI user function page.

Added the noe.spectrum_type user function page to the NOE peak intensity reading wizard.

Implemented the noe user function GUI pages and menu entries.