Pipeline requests in get_multi

Instead of doing lot's of small writes do 1 larger write. This also
considerably cuts down on locking already locked servers.
Keep existing behaviour when no server is found
Debug message instead of warning

Closer to old behaviour
1. Change Gemfile deprecated source
2. Fix Typo
3. Remove unused line
Merge pull request #342 from vipulnsward/master

Change Source, Fix Typo and remove unused line
Make get_multi go through chokepoint method
Use equality comparison from String instead of the unmarshalled response
Merge pull request #344 from theron17/master

Protect against objects with custom equality checking
Better AS instrumentation for read via fetch
Merge pull request #348 from cjbottaro/master

Better AS instrumentation for read via fetch
update Client rdoc for compress option
Merge pull request #349 from spagalloco/docfix

update Client rdoc for compress option
Update README.md

Fixing a link being interpreted as an image.
Merge pull request #351 from danielribeiro/master

Fixing Link being interpreted as an image on the README.md
Fix block-aliased variable
fix doc link
Add ruby 2.0 for travis-ci
Merge pull request #352 from sanemat/feature/ruby-2-0-0

Add ruby 2.0 for travis-ci
Add apraisal
Move appraisal gem to Gemfile from dalli.gemspec