workaround for cffi issue 140. refs #762
add MGF1 class, docs, tests
change MAX_LENGTH to be an object rather than a byte string
make attributes of MGF1 private since that's our general convention
document MAX_LENGTH
make create_modulename private, add test
be less dumb
make MAX_LENGTH an object()
Don't go via hex() when working with BNs
test IDEA key_size properly
Merge pull request #801 from reaperhulk/fix-idea-coverage

test IDEA key_size properly
Document the platforms we test on
Document Python versions too
Alphabetise
Tweak wording
restructure if statements to be less confusing
Merge pull request #802 from public/platforms

Document the platforms we test on
Merge pull request #775 from reaperhulk/rsa-mgf1-class

add MGF1 class, docs, tests
Don't put things with side effects in assert statements
Merge pull request #803 from alex/style

Don't put things with side effects in assert statements