* [ParameterValidator] Ensure context has all fields
Previously if a bridge had a set of parameters like:
const PARAMETERS = array(
'ContextA' => array(
'Param1' => array(
'name' => 'Param1',
'required' => true
)
),
'ContextB' => array(
'Param1' => array(
'name' => 'Param1',
'required' => true
),
'Param2' => array(
'name' => 'Param2',
'required' => true
)
)
)
and a query specifying both Param1 and Param2 was provided a 'Mixed
context parameters' error would be returned. This change ensures
ContextA in the above example would not be considered a relevant context.
RSS-Bridge currently has to guess the queried context from the data
provided by the user. This, however, can cause issues for bridges
that have multiple contexts with conflicting parameters (i.e. none).
This commit adds context hinting to queries via '&context=<context>'
which can be omitted in which case the context is determined as before.
Adds a new class 'ParameterValidator' to replace the functions from
'validator.php', separating private functions from 'validateData' to
class private functions in the process.
Instead of echoing error messages, adds messages to a private variable,
accessible via 'getInvalidParameters'.
BridgeAbstract now adds invalid parameter names to the error message.
