json: add json APIs

There are several changes to job and title structs that break 
current windows interop code.  The interop code should be changed
such that it only uses json APIs.  So if there is any missing
features (or bugs) in these APIs, please let me know.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6602 b64f7644-9d1e-0410-96f1-a4d463321fa5
json: fix building with qsv enabled.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6603 b64f7644-9d1e-0410-96f1-a4d463321fa5
mux: fix format of ssa preamble
sprintf decimal specifier was using the system local to insert a ','
where there should have been a '.'


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6604 b64f7644-9d1e-0410-96f1-a4d463321fa5