relax SVN archive

svn+ssh://bugman@.../svn/relax/1.3

........
r16666 | bugman | 2012-06-05 14:27:34 +0200 (Tue, 05 Jun 2012) | 3 lines

Missing import.
........
r16668 | bugman | 2012-06-05 15:17:58 +0200 (Tue, 05 Jun 2012) | 9 lines

Added checks for the proton frq for the relax_data.read and relax_data.back_calc user functions.

This is in response to the problems seen by Martin Ballaschk <ballaschk att fmp-berlin dott de> and
reported at http://www.mail-archive.com/relax-users@.../msg01179.html (Message-Id:
<533CDA92-36FE-4E36-8925-7536EFF2608E@...>).

If the frequency is not exact or is less than 1 MHz, warnings are now given to the user.
........