NAT H.323 1.4 for Linux kernel 2.6.18 released

Change log:

1. Replaced parameter callforward_filter with internal_net
2. Added support for H.323 signal proxy/softswitch
3. Added missing T.120 support in OLCA
4. Bugfix of put expectation after get.
5. Changed all helper structure definitions to meet some compilers
6. Check range first in sequence extension to save a nanosecond