.gitmodules: use relative submodule URLs

The previously configured URLs were project homepages [1], not Git
repositories [2].  Rather than hardcode a full URL here, it's probably
better to just use a relative URL.  `git submodule` interprets URLs
from .gitmodules relative to the superproject's origin, so

  $ git clone git://github.com/inducer/pycuda.git

sets up

  $ git config remote.origin.url
  git://github.com/inducer/pycuda.git

so the new .gitmodules URLs resolve to

  git://github.com/inducer/bpl-subset.git
  git://github.com/inducer/compyte.git

[1]: http://github.com/inducer/bpl-subset
[2]: https://github.com/inducer/bpl-subset.git
     git://github.com/inducer/bpl-subset.git

(reported by Philip David)

Add CUDAND log-normal generators

Alexander Harvey Nitz authored Aug 21, 2012 and Andreas Klöckner committed Aug 22, 2012

fixed mistakes in argument spacing that I introduced, added inplace division, and made abs() return a real vector type for complex arrays

Alexander Harvey Nitz authored Aug 17, 2012 and Andreas Klöckner committed Aug 21, 2012

sub now should work with complex scalars, get_axpbz_kernel now allows a different dtype for the output vectorand input vector

py.test seems to take the latter way too seriously, and the meaning
is slightly off anyway.

Array size inconsistencies in XORWOWRandomNumberGenerator