Rename simple_random module into prng
Rename simpleRand_setSeed() to prng_set_seed()
prng: Rename argument of prng_set_seed() from i_seed to seed
prng: Rename simpleRand_get() to prng_rand()
prng: Update year within copyright notice
prng.c: Rename g_lastVal to seed
prng: Refine Doxygen comment blocks
prng.c: Rename constants to be in accordance with the Wikipedia article