First checkin of incident reporting.

There are a few major pieces here:

incidentd
---------
This daemon (started by init) runs and accepts incoming requests to take
incident reports.  When prompted, it calls into various system services
and fills in an IncidentProto data structure, and then writes the report
into dropbox.

The next steps for incidentd:
    - Security review of SELinux policies. These will be a subset of
      the dumpstate permissions.  Until this is done, incidentd is
      not started at boot time.

incident
--------
This shell command calls into incidentd, and can initiate an incident
report and either capture the output or leave for dropbox.

incident_report
---------------
This host side tool can call adb shell with the correct parameters
and also format the incident report as text.  This formatting code
was left of the device on purpose.  Right now it's pretty small, but
as the number of fields increases, the metadata and code to do the
formatting will start to grow.

The incident_report command also contains a workaround to let it
work before incidentd is turned on by default.  Right now, it is
implemented to call adb shell dumpsys <service> --proto directly,
whereas in the future it will go through the full incidentd flow.

incident_section_gen
--------------------
A build-time tool that generates a stripped down set of information
about the fields that are available.

libincident
-----------
This library contains the code to connect to incidentd, and the
meta proto definitions that are used by the framework protos.
The basics are here now, but they are not fully fleshed out yet.
The privacy.proto file contains annotations that can go in the
proto file that we will later use to filter which fields are
uploaded, and which are used by local sources.  For example, a
device in a test lab is safe to upload much much more information
than a real user.  These will share the same mechanism, but the
user's output will be filtered according to these annotations.

frameworks/core/proto
---------------------
These .proto files contain the definitions of the system's
output.  There is one master android.os.IncidentProto file that
is the top level of an incident report, but some other services
(notification, fingerprint, batterystats, etc) will have others
that are used directly by the logging mechanism.

Other files which are shared by several of the services also go
here, such as ComponentName, Locale, Configuration, etc.  There
will be many more.

There is also a first iplementation of a dump method handling
--proto in the fingerprint service.

IncidentManager
---------------
The java API to trigger an incident report.

Test: Not written yet
Change-Id: I59568b115ac7fcf73af70c946c95752bf33ae67f