Fixed check_stacie_simple test.
Fixed check_stacie_simple test.

Switched the names of the initialization vector and encryption key variable names.
Added testing for new function stacie_seed_key_derive().

lavabit/magma,lavabit/magma,lavabit/magma,lavabit/magma,lavabit/magma,lavabit/magma,lavabit/magma,lavabit/magma