add tidy test for space after ":" in stucts
Addresses issue #10702
the tidy self-test doesn't seem to catch the `member_name:"Foo"` line like it should. the regex follows similar pattern in the file and works in my regex tester tool, so not really sure what is going on there.
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tidy check for vim and emacs modelines
See #10719.
It skips *.webidl files for now since I am not sure where they come from and if they should be edited in tree or not.
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This is a new attempt of #10586, after Simon Sapin's great cleanups in #10749 has landed. I have adjusted the changes to the new structure that was introduced, and also only done a few of the longhand ones. Will certainly continue on this as soon as we have a basic agreement that this style is reasonable.
- also update requriements "pyflakes" from 0.8 to 0.8.1 due to following issue
```
Traceback (most recent call last):
File "/Users/Askeing/software/servo/python/_virtualenv/bin/servo-tidy", line 5, in <module>
from pkg_resources import load_entry_point
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3084, in <module>
@_call_aside
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3070, in _call_aside
f(*args, **kwargs)
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3097, in
_initialize_master_working_set
working_set = WorkingSet._build_master()
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 653, in _build_master
return cls._build_from_requirements(__requires__)
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 666, in
_build_from_requirements
dists = ws.resolve(reqs, Environment())
File "/Users/Askeing/software/servo/python/_virtualenv/lib/python2.7/site-packages/pkg_resources/__init__.py", line 839, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'pyflakes==0.8.1' distribution was not found and is required by servo-tidy
```
