[Hugs] #81: support --version flag

[Hugs]

#81: support --version flag
--------------------+-------------------------------------------------------
 Reporter:  guest   |       Owner:  nobody
     Type:  defect  |      Status:  new   
 Priority:  minor   |   Milestone:        
Component:  hugs    |     Version:  200609
 Keywords:          |  
--------------------+-------------------------------------------------------
 Discovering hugs's version number is almost impossible and certainly
 impractical. The result is that Cabal does not know the hugs version
 number.

 As far as I can see, the only way to find the version number is to start
 hugs, grep the banner and translate textual months into a sensible version
 number, then :q to exit hugs again. Note also that hugs considers itself
 to be unversioned:

 {{{
 $ hugs -98 System.Info
 __   __ __  __  ____   ___      _________________________________________
 ||   || ||  || ||  || ||__      Hugs 98: Based on the Haskell 98 standard
 ||___|| ||__|| ||__||  __||     Copyright (c) 1994-2005
 ||---||         ___||           World Wide Web: http://haskell.org/hugs
 ||   ||                         Report bugs to: hugs-bugs at haskell.org
 ||   || Version: March 2005     _________________________________________

 Hugs mode: Restart with command line option +98 for Haskell 98 mode

 Type :? for help
 System.Info> compilerVersion
 Version {versionBranch = [0,0], versionTags = []}
 System.Info>
 }}}

 Version 0.0 eh?

 Most programs support a --version command line flag that spits out the
 version number (and sometimes some other (un)helpful information) and then
 terminates.

 As for the format, I'd suggest:

 {{{
 hugs --version
 Hugs version 2006.9
 }}}

 That is, a version number that can fit into the Data.Version format.

 The reason this is important for Cabal support is that it'd allow Cabal
 itself or packages (via configurations) to conditionally enable/disable
 support for features depending on the version of hugs.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/81>
Hugs <http://www.haskell.org/hugs/>
Hugs 98, an interpreter for Haskell