Laid groundwork for custom Memcached key serializers
Introduce MemcachedKeySanitizerLike for pluggable MemcachedKeySanitizer strategies

Mainly to allow the use of hashing for MemcachedKey sanitising

1. Added MemcachedKeySanitizerLike as a trait
2. Redefined MemcachedKeySanitizer as ReplaceAndTruncate
3. Added HashingMemcachedKeySanitizer that takes a HashingAlgorithm as an argument. This classes basically sanitises by using the hashing algorithm
4. Add tests
Somehow renaming a class renamed the file. Fixed
Add non-ASCII char test
Use MessageDigest properly. Apparently it isn't thread-safe.

Added a regression test as well.
Add IntegrationPatience for slow CI service
Add Scaladoc
Merge pull request #8 from lloydmeta/feature/memcached-key-hashing

Feature/memcached key hashing