[PATCH] libecap v1.0 support

Hello,

    The attached patch upgrades Squid to libecap v1.0, allowing
asynchronous (e.g., threaded) eCAP adapters and eCAP version checks.

After these changes, Squid can support eCAP adapters built with libecap
v1.0, but stops supporting adapters built with earlier libecap versions
(due to libecap API changes). The new libecap version allows Squid to
better check the version of the eCAP adapter being loaded as well as the
version of the eCAP library being used. This should help with migration
to libecap v1.0.

Thank you,

Alex.