Fixed typo.

This typo doesn't actually cause any side effects unless you are like
stqism and have a C library that doesn't have mempcpy().
Fixed TOX_MAX_MESSAGE_LENGTH define.

Removed some useless code from toxcore.

Astyled core code with new version of astyle.
tox_test now checks if TOX_MAX_MESSAGE_LENGTH is correctly set.
Increased some timeouts to try to prevent disconnections when
transferring files on wireless networks.
Added instructions on how to pause/resume file transfers.
This might fix the issue that someone reported about tox no longer
cross compiling for windows.
Tweaked file transfers a bit.
Added data packet padding to toxcore.

Data sent as lossless or lossy is now padded with:
((MAX_CRYPTO_DATA_SIZE - data_length) % CRYPTO_MAX_PADDING) bytes
in order to reduce the possibility of length related attacks.

I set CRYPTO_MAX_PADDING to 8 but it can be changed anytime without
breaking network compatibility between tox cores.
Request packets are now sent with send_data_packet_helper().

This means all data packets are now padded the same way.
Doubled minimum transfer rate.

File transfers got stuck because it was too low.
Fixed bug when passing invalid call index
Merge branch 'mannol1-master'
Optimized net_crypto UDP packet sorting using list.
Removed useless code
Fixed regression that made packet_send_rate increase even when
no data was transmitted.
Fixed possible bug in list.
Kill toxes when finished in tox_test to test tox_kill.
Renamed list functions to fix conflict issue on certain machines.
Updated outdated crypto doc.
Updated documentation.