clean up warnings. 3 left on 1.0.1e, 21 left 0.9.8y (OS X)
2 more warnings fixed (on both 1.0.1e and 0.9.8y)
fix last warning (macro returns ASN1_ITEM_EXP *)

* 0 warnings in OpenSSL 1.0.1e
* 18 warnings in 0.9.8y
fix a style error
Merge pull request #349 from reaperhulk/compile-warnings

Reduce Compiler Warnings