Make haskell-process-do-info prompt on prefix arg.

@hvr FYI
Add haskell-presentation-mode and option.

@hvr might be of interest.
Support popups from popups.
Forgot that this function is used in contextual-space.
Move session assigning to haskell-process.

@hvr this avoids the dependency problem.
Woops, forgot this part.

@hvr
Use silent queueing function.

@hvr FWIW.
Unify Elisp boilerplate headers

This makes the Elisp headers conform to the conventions described in

 http://www.gnu.org/software/emacs/manual/html_node/elisp/Library-Headers.html

The obsolete `haskell-string.el` has been left out, as it's going to
be removed soon (see d6b83169 for more details)
Remove trailing whitespaces
Replace literal TAB by escaped `\t` in regexp
Untabify Elisp source files

Care has been taken to avoid replacing TABs by spaces in regexps
(such as in 05fe83b).