Clean up debug, add some more debug, and move request error slots to Request base class

Use LOG_DEBUG() instead of qDebug() etc.

All the error slots have the same implementation, so just move this
to the base class.
Send the full URL for event update requests

The URL can't be just composed from the host and path as this removes
necessary URL information, e.g. the scheme.
Update last sync time when a sync finishes, and remove syncFinished() signal

Whenever a sync ends, mResults must be reset with the current
date/time so that this will be set by the buteo framework as the new
lastSyncTime in the sync log. Otherwise, the lastSyncTime will refer to
the time at which the sync session started, which means any events
received during the session will be seen as "new" events during the next
sync session, and will cause the client to try to send these as new
events to the server, which will fail.

This also renames receiveSyncFinished() to syncFinished() and removes
the existing syncFinished() signal as it was only used internally and
was always forwarded to receiveSyncFinished().
Don't do a GET after a PUT as it will fail, and the client follows up with a REPORT anyway

The GET is only required to retrieve the updated etags of the files
sent by the PUT, and this is not necessary since caldavclient sends a
REPORT at the end of each sync, which will cause it to receive the
updated etags without an extra GET request.

Additionally, the PUT was always failing as its result depended on
the following GET, which fails as it attempts to read the received
body data in xml instead of vcal format. This patch changes the
GET response processing code to always emit finished().
Use lastSyncTime() from iProfile and shift the db offset to startQuickSync()
Add '/' to end of remote database path

The client plugin relies on this being present in other operations.
Remove stateChanged() and receiveStateChanged()

These are not used in the client at the moment. They can be re-added
later on if necessary.
Send correct path for DELETE requests

Fix to send the amended uri. It should also have an ".ics" extension.
Ensure buffer objects are deleted
Save and retrieve settings from a specific service rather than the global service

Read the specific service name from the profile settings and use
this service when saving and retrieving all account settings instead
of just using the (default) global service.
Ensure QNetworkReply objects are deleted when requests finish

This also removes the mNReply member variable since the slot can
access the reply object with the sender() method.
Only process body data if request was successful, and ensure DELETE and REPORT requests always emit finished()
[caldav] Fixes following patch review

- Fail authentication if existingIdentity cannot be loaded
- Fail authentication if credentials ID does not exist for the service
- Add default switch handler in CalDavClient::syncFinished()
- Fix copyright headers
Merge pull request #2 from nemomobile/more-fixes

More fixes