RC2: Optimizations, inline-crypt bug fix


Hi Patrick... great work!  re: https://github.com/phpseclib/phpseclib/commit/b247ad174375dbdc323a85a2e2f82d10c3b225c7

i made some changes in _setupInlineCrypt(). Speeding it up to additional ~20% and fixing a "code-layout" bug in there.

Also i made some other changes arround (typo, memory optimization, phpdoc, CS). See the inline github comments.

For ```setKey($key, $t1 = 1024) ```
Do you think it's possible - if it makes sense - to remove the second parameter and add a public method like "setEffectiveKeyLength()" ... as we do it similar in Rijndael with setKeyLength()
I ask this only, trying to be syncron with the other ciphers setKey() arguments and object handlings (as good as possible :-) )

Greetings
Hans-Jürgen :-)