Removed define that could become confusing.
Adding encrypted data to send/getnode packets part 1.
Added symmetric crypto functions to net_crypto.
Astyled some files.
Adding encrypted data to send/getnode packets now done.
Removed now useless ping_id from send/get node packets.
Fixed build error with libsodium.
Base of hardening stuff.
Clarified a comment.
Small changes to A/V
Merge pull request #633 from Martijnvdc/master

Small changes to A/V
Increased port range.
Merge branch 'master' of https://github.com/irungentoo/ProjectTox-Core
Added some hardening functions to test get nodes.
Cleaned up some code/fixed some warnings.

I'm sure nobody has any of the old save files anymore so I removed the
functions.
Public headers should not have any internal references
Merge pull request #634 from jin-eld/fix-public-headers

Public headers should not have any internal references
added AV_codec.h to public headers
renamed AV_codec to toxmedia
Merge pull request #635 from Martijnvdc/master

added AV_codec.h to public headers