Convert more implicit intents to explicit ones

Removed AsyncServiceTask String only constructor, as it should always be
called with an *explicit* intent. Changed outgoing filetransfer API so
that the Service class is handed over, instead of the Intent action,
which is now per definition

pkg + ".OUTGOING_FILETRANSFER_SERVICE"

The fileread outgoing filetransfer, i.e. the 'send' command, no uses
AsyncServiceTask with an explicit intent.
transport-xmpp: Improved log of ConnectionExceptions
transport-xmpp: Changed aSmack version to 0.9.0-SNAPSHOT-2014-03-23
Catch exception in unbindService of AsyncServiceTask

Sometimes when the service binding fails (for whatever reason),
unbindService will throw an "IllegalArgumentException: Service not
registered".
transport-xmpp: Whitelist all service components

when privacy lists are in use.

Previously, service components like "proxy.service.com" would be blocked
by privacy lists, disallowing file transfer in certain situations.
transport-xmpp: Add workaround for LastActivityManager

For some reason the static initialization block of LastActivityManager is
not run. We workaround this in XMPPService by explicitly setting
setEnabledPerDefault() to true, which is already Smack's default, so
that the static initialization block is run.