Implements a small language parser to define the emulator events. The
event specification is parsed at emulation (when the emulator runs).
The ovnidump output now prints the events with the arguments formatted
as given in the event description.
It also introduces some consistency checks over the event MCVs, which
must begin with the model identifier and cannot be duplicated.
The experimental flag -a is used to ease the transition to the usage of
ovni_thread_require(), as it may be posible to have traces in which not
all libraries have requested their model. The flag causes all emulation
models to be enabled. This flag is considered experimental and it may be
removed or renamed in future versions.
Allows programs to update to a new libovni library without breaking the
instrumentation. Only until the first call to ovni_thread_require() the
models are enabled on demand.
Traces with metadata version 1 don't use per-thread information, so we
cannot read the 'require' key. All models will be enabled for old traces
(which will cause performance problems).
Until now, emulation models were always being registered via probe(),
which causes the emulator to initialize all the channels. To reduce the
overhead, the channels were not connected or registered in the bay
until the first event of that model was received. This delayed connect
was causing issues in muxes where the newly connected model required
refreshing the touched channels. Which in turn was causing unexpected
PRV events.
By determining which models we need to enable, we can remove the delayed
connect mechanism and just enable those models at initialization time,
and connect the channels.
