Added the concept of a layer service.  Layer services allows to to create resource/dispatch presets for particular applications.  For example if you always want your maya renders have a minimum of 2 cores, then you would set that in your maya service definition.
Added "is set" columns to the service table which are set to true if the value should be used, false if not.
Switched layer tags to be a list
Added a layer prep stage to job launching that applies the service settings to the layer, if any.
Fixed mix ups with building a ServiceFull object.
Default chunk to 1
Naming cleanups
Fixes issue with wrong value from a service being for tags and threadable.
Added maxRam and maxRetries to layer insert.
Added  maxRetries to thrift layer.
Added int_retries_max column to layer table.
Fixes and issue with setTags not being set.
Created unit test which tests values coming from a service.
Added more tests to ensure layer settings can be overridden correctly.
Layer tags should be a list.
Fixes client compile issues after changing layer tags to a list.