Networking is not allowed on the main thread, and on some devices with strict
mode on, even the creation of the http handler is enough to trigger an
exception (i.e even if not used from the thread).
This moves even the creation to a thread which fixes the issue.
HTTP requests and responses are logged when logging to file. Until now,
only the existence of requests was logged. With this change, also the
content and headers of the requests and responses is printed to the log.
Before this change we were printing added/changed contacts and groups
to the adb log. This is not a big deal on its own, but now since we
have ACRA, we share these logs on crash (if user approves) so it's
better to remove personal information to make sure it's not being
accidentally shared.
Android annoyingly kill sync managers that don't have a significant
amount of network traffic within a given minute. This means that if we
have a lot of entries to process, we may get killed by the system if we
have a lot of entries to prepare for pushing. We were sending in chunks,
for network performance, but now we make the whole process work in
chunks.
This should fix an issue reported by a user who imported a significant
amount of contacts in one go.
This is similar to the issue fixed for fetch in:
f7104bbcef
We were doing it to make sure we don't get overridden by
server changes. But we already changed this behaviour in
the past, so this call was just doing nothing and slowing
down the sync.
This was causing issues when importing from a Google account in some cases
because we were getting weird UIDs.
This was also problematic when importing from other sources that
reported weird UIDs.
