ECB vectors for the IDEA cipher.

Vectors from NESSIE and reformatted for NIST loader.
https://www.cosic.esat.kuleuven.be/nessie/testvectors/bc/idea/Idea-128-64.verified.test-vectors
update IDEA ECB vectors to contain 100/1000 iteration results
add vector source data for IDEA ECB to docs
Merge pull request #395 from reaperhulk/idea-vectors

ECB vectors for the IDEA cipher