Backport PRE/POST-raw-processing and related fixes.
spiral: Add Call-ID mangling support. Dialog module not needed.
spiral: Replace strncmp with memcmp when appropriate.
spiral: Work with the new module dependency specification interface.
spiral: Add sipp tests.
spiral: Add via cookies to tackle the failing cases.
spiral: Improve tests. Check 404 too.
spiral: Improve tests by adding a CANCEL test case.
spiral: Fix CANCEL behaviour (and CANCEL test).
spiral: Fixes for backport to 1.10.