OTCrypto/OTCrypto_OpenSSL basic split into two files. Cleanup pending...
Made GetPasswordFromConsoleLowLevel abstract.
Moved concrete implementation to OTCrypto_OpenSSL.
Remove unneeded includes.
Choose OTCrypto implementation via a typedef
Applied clang-format
Removed commented code.
Merge pull request #249 from benma/issue236

Resolves #236 (Split OTCrypto files into interface and implementation)