Improve OS DSNAME validation. Valid characters are A-Z, 0-9, #, $, @, -, { and '.'

git-svn-id: file:///home/jj/hercules.svn/trunk@7367 956126f8-22a0-4046-8f4a-272fa8102e63
dasdls: show various info from F1 DSCB
Documentation for dasdls enhancement

Adapted from Chris Cheney's Documentation, in the style of the
Hercules Operations and Utilities manual, which can be seen at
http://k9.bitbucket.org/hercules/dasdls.html