[PATCH] certificate_db/ssl_crtd fixes

certificate_db/ssl_crtd fixes

- Try to update the index file in all cases the database modified

- The find operator in database should not modify the database.
Currently if an entry is expired, ssl_crtd removes the cert file but
does not update the index file.

- Use OPENSSL_malloc and OPENSSL_free to allocate/release memory for
TXT_DB rows. Currently we are using the new operator.

- Fix a small memory leak when remove entries from database: A row
object removed from TXT_DB indexes but never released. This patch:

     * Use OPENSSL_malloc and OPENSSL_free to allocate/release memory
for TXT_DB rows. OpenSSL SDK assumes that always allocated using these
functions.

     * Add code in Ssl::CertificateDb::Row destructor to correctly
release a TXT_DB row. The code take cares for rows allocated internally
by OpenSSL SDK.

     * Add the sq_TXT_DB_delete and sq_TXT_DB_delete_row functions which
removes a row from TXT_DB indexes.

The patch applies as is to squid-3.3. A patch for squid-3.2 is included

This is a Measurement Factory project