Merge pull request #231 from maksimov/develop

Adding SpotPrice timestamps filtering
WIP: Spot Instances rework
Checkstyle fixes
Spot VMs re-work cont: floats for prices are back for consistency with the rest of the API.
Added abstract methods

Added some missing abstract methods for VLANSUpport
Merge Fixes
Merge pull request #233 from andylyall/develop

Develop
Replaced take-all getInstance method with a single parameter method taking only mandatory spot price
Merge branch 'develop' of github.com:maksimov/dasein-cloud-core into develop