Merge pull request #763 from mannol1/master

Pkg-config config for av
Update INSTALL.md
Speeded up DHT peer finding and decreased DHT bandwidth usage.
Merge pull request #764 from mouseym/patch-2

Update INSTALL.md
Added bound checking for friend ID input in DHT test
bound checking in messenger testing
Merge pull request #768 from seshagiriprabhu/buffer_overflow_in_testing

Added bound checking for the client id of the friend input in DHT test
Allow to optionally use randombytes_stir() instead of sodium_init()

According to sonOfRa sodium_init() has some timing issues on Android.
libsodium people said randombytes_stir() can be used instead:
https://github.com/jedisct1/libsodium/issues/121

sodium_init() stays the default, randombytes_stir() can be enabled by
passing --enable-randombytes-stir to the configure script.
Merge pull request #769 from jin-eld/alternative-sodium-init

Allow to optionally use randombytes_stir() instead of sodium_init()
Main buildscripts for android
Merge pull request #765 from Prototik/master

Main buildscripts for android
Major speed/cpu usage/bandwidth improvements to onion.
Fixed/updated tests.
Merge branch 'master' of https://github.com/irungentoo/ProjectTox-Core
Fixed onion test.
Very simple fix to lower bandwidth usage at startup.
Some small DHT CPU optimizations.

Only compute the shared key once instead of twice for received DHT
requests/responses.
Small CPU optimizations to ping requests/reponses.

Same idea as last commit.
Some CPU optimizations and fixes to onion_announce_request.
Made onion paths expire eventually client side.