On 4679fbee41, rebuild was disabled on
CHMOD filesystem events, but the code is overly aggressive.
In some situations, specially with older Mac's (using a Late 2008
Macbook), the events we receive might be aggregated. On my
particular laptop, I get this events:
INFO: 2016/07/26 18:08:51 hugo.go:737: Received System Events: ["<path>": WRITE|CHMOD]
These events are ignored because the code only checks for Chmod. This
commit fixes this by checking that the event is also not a Write or Create.
Related to #1587.