Vala 0.51.91
============
 * Various improvements and bug fixes:
  - codegen:
    + Error for missing type-arguments of HashTable (de)serialization [#1147]
    + Free intermediate temp-variables of postcondition expression [#80]
    + Use the one available source_reference for internal error [#436]
    + Fix access to captured generics in async method of interfaces [#537]
    + Don't ever create null-aware free macro for GenericType
    + Don't add generics arguments/parameters to async finish method
    + Drop inner casts before converting between generics and integers
  - vala:
    + Add missing null-check in DataType.get_type_signature()
    + Check array type of declarations for errornous type-arguments
    + Check (optional) type-arguments of array creation expression
    + Replace all type parameter occurances in parameters for signal delegate

 * Bindings:
  - glib-2.0,gio-2.0: Add some missing type-arguments
  - vapi: Update GIR-based bindings