conda recipe and binstar build yml file

This aids building bcolz with conda and hosting conda builds on binstar-build.

Note that the Blaze channel is [hosting bcolz builds](binstar.org/blaze/bcolz/builds) for all platforms and common Python versions.  These are accessible via the following:

    conda install -c blaze bcolz

This doesn't require a compiler and tends to point to something closer to git master than the main conda channel.

Also, just for acknowledgements, I stole a fair amount of this work from others, notably @cpcloud .
Here is the section from the Bash Manpage:


```
   Command Substitution
       Command  substitution  allows  the  output of a command to replace the
       command name.  There are two forms:

              $(command)
       or
              `command`

       Bash performs the expansion by executing  command  and  replacing  the
       command substitution with the standard output of the command, with any
       trailing newlines deleted.  Embedded newlines  are  not  deleted,  but
       they  may  be removed during word splitting.  The command substitution
       $(cat file) can be replaced by the equivalent but faster $(< file).

       When the old-style backquote form of substitution is  used,  backslash
       retains  its  literal meaning except when followed by $, `, or \.  The
       first backquote not preceded by a  backslash  terminates  the  command
       substitution.   When using the $(command) form, all characters between
       the parentheses make up the command; none are treated specially.

       Command substitutions may be nested.  To nest  when  using  the  back‐
       quoted form, escape the inner backquotes with backslashes.

       If  the  substitution appears within double quotes, word splitting and
       pathname expansion are not performed on the results.
```

And so I *guess* in this case the only argument for ``$()`` is style.