Merge branch 'u/jdemeyer/ticket/16827' of git://trac.sagemath.org/sage into ticket/16955
Preparse file foo.sage to foo.sage.py
Clean-up: remove references to Mercurial branches, devel/sage
Make sage -b interruptable
Merge commit '17ad642b0f01e6411b2edf444ce53ea1813bacf3' into HEAD

Conflicts:
	src/bin/sage-preparse
Trac #16113: Ctrl-C while sage -b

Interrupting (Ctrl-C) in the parallel builder for the sage extension
modules (`sage -b`) sometimes doesn't work.

Steps to reproduce:
* sage -ba
* press Ctrl-C after the cythonization started

URL: http://trac.sagemath.org/16113
Reported by: vbraun
Ticket author(s): Volker Braun
Reviewer(s): Jeroen Demeyer
Trac #16955: Give safer names to preparsed files

If you run `sage new.sage` on a script `new.sage`, it creates a
preparsed file `new.py`.  Then when a file in the twisted package tries
to import the `new` Python module, it ends up importing this preparsed
file instead, which leads to problems which can be hard to track down.

I can think of several solutions:

 1. hope that users will know not to use names like `new.sage`.  This is
the current state of affairs, and it seems overly optimistic to me.
 2. give a warning, or fail outright with an error, if the name of the
file is the same as that of a Python module.
 3. name the preparsed file something which is less likely to cause a
clash, for example, turn `file.sage` into `file.sage.py`.
 4. don't save the preparsed file at all: use a pipe to transfer the
preparsed file to Python (see #11821).

The goal of this ticket is to implement 3 (which is interestingly what
is documented in `./sage --help`)

URL: http://trac.sagemath.org/16955
Reported by: jdemeyer
Ticket author(s): Jeroen Demeyer, John Palmieri
Reviewer(s): John Palmieri
Trac #16962: clean-up: remove some references to Mercurial branches and devel/sage

As the summary says, there are still some references to
`devel/sage/sage/...` and to Mercurial branches. Remove these.

URL: http://trac.sagemath.org/16962
Reported by: jhpalmieri
Ticket author(s): John Palmieri
Reviewer(s): Jeroen Demeyer