RSA: add support for saving to PKCS8 (unencrypted)
Crypt/Base: add support for pbkdf1
RSA: add support for loading PKCS8 encrypted private keys
Crypt/Base: adjust default key size for pbkdf1
RSA: add support for saving encrypted PKCS8 keys
RSA: add PKCS8 unit tests
RSA: rename PUBLIC_FORMAT_PKCS1_RAW -> PUBLIC_FORMAT_PKCS8

also make CRYPT_RSA_PUBLIC_FORMAT_PKCS8 the default format
RSA: CS adjustments
BigInteger: make it so you can do $min->random($max)

...and $min->randomPrime($max) as well
BigInteger: fix syntax error
BigInteger: fix unit tests
BigInteger: change argument names for random / randomPrime
BigInteger: unit test update
BigInteger: update comments
BigInteger: one more change to the comments
Random: include the Crypt_* classes if they're available

also error out if none are available
Always correctly link to the constructor of Crypt_Base.
SSH2: replace _is_includable() with stream_resolve_include_path
Random: add explanatory comment
Merge pull request #373 from terrafrost/another-random-change

BigInteger: make it so you can do $min->random($max)

* terrafrost/another-random-change:
  BigInteger: one more change to the comments
  BigInteger: update comments
  BigInteger: unit test update
  BigInteger: change argument names for random / randomPrime
  BigInteger: fix unit tests
  BigInteger: fix syntax error
  BigInteger: make it so you can do $min->random($max)