Added system memory info output

Related-Bug: #1364469
Change-Id: I4a987432b7843c5d2a761ea98755c513dc44096d
Fixes bug with put item predefined attributes

Fixes bug that prevents setting to 'null' item
predefined attributes, that are not mentioned
in put request.

Closes-bug: #1348336
Change-Id: I5ad0db7ea81224c2a6f42a4f792f1dbf28f85c90
Adds mechanism for request time measuring

Implements: bp application-instrumentation
Change-Id: Id9fe1b4cc5351ac3636dbf46bf7c1c514dc9ea80
Merge "Fixes bug with put item predefined attributes"
Merge "Adds mechanism for request time measuring"
Add queued storage manager

Change-Id: Ibcb05258f2644fac46c783f46429c0761f802744
Implements: async-shema-operations