[PERDITION-USERS] Escaping of ldapi:// URIs (1.19rc4)

When connecting to an LDAP server with the ldapi: URI scheme (using a UNIX domain socket), the "host" portion of the URI contains the full path to the socket special file. Forward slash characters in the path must be URL-escaped to avoid confusion with the slashes that delimit the components of the URI itself. The function perdition_ldap_uri() in perdition/db/ldap/perditiondb_ldap.c doesn't handle ldapi:// URIs in any special way, which makes it impossible to use such URIs for contacting the LDAP server. The attached patch adds ldapi:// recognition and path escaping to that function. i.