Moved Bunch of functions from net_crypto to crypto_core.
decrypt_data_fast and decrypt_data_symmetric were the same thing
therefore, removed decrypt_data_fast.
Replaced all the crypto_secretbox_* defines with the equivalent
crypto_box_* one.
New define: crypto_box_KEYBYTES that is equal to
crypto_box_BEFORENMBYTES.
By default libsodium is used. Only if --enable-nacl is specified, then
nacl will be used instead of libsodium.
Pass locations of nacl headers and libraries by using the following
options:
--with-nacl-headers=/home/me/somewhere/nacl-20110221/build/469/include/amd64/
--with-nacl-libs=/home/me/somewhere/nacl-20110221/build/469/lib/amd64/
While doing the checks configure might generate "core" files and will
then try to remove them. Having a "core" directory generates an error
while runing the configure script.
There's no workaround but to rename the core directory.
