Don't require 2to3 for astropy.vo.samp
PEP8 Fixes
Clarify ``callable`` option
Set a timeout for the web profile test
Fixed a few more very long lines
Tidied up long lines in hub.py and fixed a docstring error in SAMPClient
Removed unused code
Fixed a few API links
Fix bugs related to using SSL in SAMP clients, which solves the previously failing tests.
Fix call_and_wait test
Use a random port for web profile tests
Fixed web profile test on Windows, and remove unused imports from tests
Fix standard profile code for Python 3.1
Make sure tests use ALLOW_INTERNET set to False, and also make sure that internet_on() doesn't raise any exceptions.
Add `one` as shortcut to `dimensionless_unscaled`

I find creating dimensionless `Quantity`es overly painful compared to quantities with dimensions. Currently the two existing options are:

1. Putting `u.km`, `u.s` next to `u.dimensionless_unscaled`. Too large.
2. Putting `u.km`, `u.s` next to `u.Unit('')` or `u.Unit(1)`. Why the inconsistency?

I find dimensionless quantities very convenient, and hence this tiny addition. It's the shortest and least obstrusive way I found to use them.

```
a = 1.0 * u.AU
ecc = 0.0167 * u.one
inc = 0.0 * u.deg
...
```
Moved u.one, added test and entry in CHANGES.rst
Fixed missing member in units.core
Merge pull request #1980 from Juanlu001/patch-1

Add `one` as shortcut to `dimensionless_unscaled`
Added automodsumm_writereprocessed sphinx configuration option
Xfail HTTPS tests on Python 3.1