[Rivet] Disabled rivetgun-static by default

[Andy Buckley]

The SVN head version of RivetGun now doesn't build rivetgun-static by default:
you have to explicitly run configure with the --enable-static flag to get it
built and installed.

This is just another little social obstacle to discourage users/developers from
using rivetgun-static and to put efforts into the main rivetgun executable
instead :) I'd be very grateful if those of you who've been working on AlpGen
and Charybdis can try them out via the main "rivetgun" command: let me know
what inevitable problems you find!

Andy

-- 
Andy Buckley: CEDAR @ IPPP, Durham
Work: www.cedar.ac.uk
www.insectnation.org