apl_crypt: Update function descriptions
apl_crypt: Add apl_encrypt_write function

Encrypt plaintext and write the ciphertext directly into a file
apl_gradebook: Gradebooks store their entry capacity

Adding entries extends the capacity when there is no more space left
apl_gradebook: Add apl_appendentry function

Add a new entry to the gradebook
test/gradebook: Test adding entries to a gradebook
apl_gradebook: Update apl_appendentry function description
Merge branch 'master' into crypt
apl_gradebook: Fix realloc size of entries list
test/gradebook: Heap allocate and init label buffer

Valgrind gets picky with uninitialized addressable memory.
Replace malloc's with calloc's

To appease Valgrind and its picky behaviors when it comes to
addressable memory
Merge branch 'master' into crypt