Fix new tabs overriding default syntax rules

Calling `syntax on` will override existing syntax rules with default
ones. This ends up adding a bunch of syntax rules that users have
disabled.

See `:help syntax` for this snippet:

    The ":syntax enable" command will keep your current color settings. This
    allows using ":highlight" commands to set your preferred colors before or
    after using this command.  If you want Vim to overrule your settings with
    the defaults, use: `:syntax on`

Calling `:syntax enable` doesn't appear to work either. It does the same thing
as `:syntax on`. So the solution implemented here is to conditionally set the
filetype and syntax rules when they aren't already set.
added :Pyedit vim command

    :Pyedit [++opt] [+cmd] module

    module is a python module, there is a completion for them as well.
    [opt] and [cmd] are like for the :edit command.
g:jedi#quickfix_window_height

    This commit adds an option g:jedi#quickfix_window_height, with the
    default value 10 (as this is the default value for :copen)
new jedi version also in sub repository
add doc/tags to gitignore
ctrl space cycles now through results, when used multiple times, fixes #118
Merge branch 'master' of git://github.com/coot/jedi-vim into pyedit
improve indentation of #117
Merge branch 'bugfix-newtab-syntax' of git://github.com/artnez/jedi-vim into newtab
use is_keyword instead of hack
Merge branch 'dev' into newtab
renamed Pyedit to Pyimport, refs #117
Fix some errors when vim is compiled with +python3.

When vim is compiled with `-python` and `+python3`, jedi-vim generates
errors because of two points in the code which are not compatible with
Python 3 (because of the `str`/`unicode` vs. `bytes`/`str` thing).
Merge pull request #135 from mlmoses/fix-python3-errors

Fix errors when vim is compiled with +python3.
Fix complete() deprecation.
Fix show_pydoc() get_definition() deprecation.
Fix get_definition() deprecation.
Fix goto() deprecation.
Fix related_names() deprecation.
Fix get_in_function_call() deprecation.