Vala 0.48.22
============
 * Various improvements and bug fixes:
  - codegen:
    + Correctly handle chain up of struct creation methods [#1264]
    + Use a dedicated EmitContext for _variant_get*() functions
  - vala:
    + NullLiteral is not a valid argument for string concatenation [#1260]
    + Set is_yield_expression in async context when chaining up to async base ctor
    + girparser: Avoid possibily creating duplicated attributes
  - vapigen.m4: use $PKG_CONFIG_SYSROOT_DIR

 * Bindings:
  - glib-2.0: Always use the actual C type for CCode.array_length_type
  - gstreamer: Cherry-pick bindings fixes from 0.56