This can happen when the user inserts a candidate string like "operator[]" which
doesn't end with an identifier char. A very obscure bug, but a bug nonetheless.
This means we can now load just ycm_client_support (which is a much smaller
library) into Vim and ycm_core into ycmd. Since ycm_client_support never depends
on libclang.so, we never have to load that into Vim which makes things much,
much easier.
For instance (`|` represents the cursor):
1. Buffer state: `foo.|bar`
2. A completion candidate of `zoobar` is shown and the user selects it.
3. Buffer state: `foo.zoobar|bar` instead of `foo.zoo|bar` which is what the
user wanted.
This commit resolves that issue.
It could be argued that the user actually wants the final buffer state to be
`foo.zoobar|` (the cursor at the end), but that would be much more difficult
to implement and is probably not worth doing.
Fixes#374.
