This doesn't need any interacion of the user at startup, unlike
retroshare-nogui which requires the user to login on the shell this doesn't
even need a TTY.
At startup this just parse command line, read the PGP keyring, look for
available locations, and start listening for JSON API requests.
Another difference with retroshare-nogui is that this is capable to
generate/import PGP identities, generate locations, and in general anything
possible through the RetroShare API.
retroshare-service is suitable also to run it as a system service, even
in very constrained systems such as Android ot a Docker container.
retroshare-service drop support for libresapi so only the new JSON API
is exposed, it will completely obsolete retroshare-android-service once
retroshare-qml-app is ported to the new JSON API.
Avoid the need of dirty patching to set the version at build time
In case RS version is not passed as argument attempt to determine it
using git describe, if unavailable use hardcoded default
qmake file add jsonapi-generator target to compile JSON API generator
qmake files add rs_jsonapi CONFIG option to enable/disable JSON API at compile
time
RsTypeSerializer pass down same serialization flags when creating new context
for nested objects serial job
RsGxsChannels expose a few methods through JSON API as example
Derive a few GXS types (RsGxsChannelGroup, RsGxsChannelPost, RsGxsFile,
RsMsgMetaData) from RsSerializables so they can be used for the JSON API
Create RsGenericSerializer::SERIALIZATION_FLAG_YIELDING so JSON objects that
miss some fields can be still deserialized, this improve API usability
SerializeContext offer friendly constructor with default paramethers
Add restbed 4.6 library as git submodule as most systems doesn't have it yet
Add a bit of documentation about JSON API into jsonapi-generator/README.adoc
Add JsonApiServer class to expose the JSON API via HTTP protocol
Since DATA_DIR (and the others) are not set 'make install' will move the files to /{qss, sounds, stylesheets, usr, webui} (instead of '/usr/...')
Fixes 4876a0ea3b
