Cpymad

- replace -flto by -fno-lto in .github/build/manylinux1/cpymad.sh causing segfalt in makethin (see https://github.com/hibtc/cpymad/issues/67)

- update to MAD-X 5.06.00
- show empty tables as empty rather than raising exception (57)
- produce windows builds with msys2/mingw-w64 toolchain. No more dependency on
older MSVCRT dlls. Let's see if there will be any runtime errors from this.

- add ``limits`` parameter to ``Madx.match``
- try to download and build MAD-X in setup.py if it is not already available

Increase test coverage up to ``96%`` (from 75), and fix a few minor bugs
detected in the tests:

Command composition:
- handle composite ranges (``A/B``) in
- fix AttributeError when composing command with equality ``Constraint``
- fix incorrect output for STRING_ARRAY range parameters (MATCH)
- fix passing ``Range`` objects as ranges

Misc:
- fix table column names being ``bytes``, return as unicode ``str``
- fix the ``sectortable2`` method
- add ``Madx.options`` property that allows to view the current set of options
- remove unused helper method ``Sequence._parse_range``
- return the cloned element from ``Element.clone``

- add MAD-X specific metadata in cpymad.madx.metadata
- speedup Travis testing (using caches and docker containers)

- update to MAD-X 5.09.03