[Hackage] #452: Improve --help. Add info about installing specific versions and the use of predicates

[Hackage]

#452: Improve --help. Add info about installing specific versions and the use of
predicates
----------------------------+-----------------------------------------------
  Reporter:  guest          |        Owner:         
      Type:  enhancement    |       Status:  new    
  Priority:  normal         |    Milestone:         
 Component:  Cabal library  |      Version:  1.2.3.0
  Severity:  normal         |     Keywords:         
Difficulty:  normal         |   Ghcversion:  6.8.3  
  Platform:                 |  
----------------------------+-----------------------------------------------
 It is possible to install a specific version of a package with the
 following syntax.

 cabal install <package>-<version>
 e.g. cabal install haskell-src-exts-0.4.3.1

 However, no mention is made of this in the --help.

 Also, it is possible to use predicates. e.g. cabal install haskell-src-
 exts<=0.4 to install a particular version of a package.
 This should also be mentioned in the --help (along with a helpful remind
 to quote the ">" character with "\>" if you don't want to redirect your
 output in most shells!

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/452>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects