[INTERNAL] sap.ui.model.odata.type.DateTimeOffset

PS2: improvements, AnnotationHelper
PS3: reviewed
PS4: reviewed, JSDoc
PS5: rebased
PS6: rebased, mock response and annotations updated
PS7: mock response updated again
PS8: fixed annotation helper test

Change-Id: I5986709d5eb37f9eb1f0043b1acd5fba6b10d90f
JIRA: FLPUISERVICES2014-1091
Merge "[INTERNAL] sap.ui.model.odata.type.DateTimeOffset"