Check for network connectivity.

Signed-off-by: Jacky Alciné <me@jalcine.me>
Merge pull request #39 from jalcine/patch/work-offline

Quietly Fail when Offline
Start splitting up the plugin
Minor cleanup
Insertion works
Patching working
Iron out minor kinks
Some initial comment support
Return from a mountain of ugly code
Fix issue with buffer attempting to replace itself
Fix omnicomplete
Adding issues works as expected
Remove unwanted newlines
Allow reloading issues
Make function names a little less stupid
Add mappings to Gissues
Support omnicomplete when constructing issues
Buffer handling improvements
Add ability to open/close issues

Update #41 Update list and issue view
Add colored labels to Gissue list

Update #43