[FEATURE]m.Column: Display popin without header.

- new WithoutHeader option is added into sap.m.PopinDisplay enumeration
to show the cell content alone without column header.
- This feature can be used when the cell content is explain itself. e.g.
Map, Chart, Description

Change-Id: I5a78b4526ce2ada074726b5aaad829b131e55068
[INTERNAL] Minor fixes to margin samples and qunit tests

Change-Id: I145cfea20652d960544edd1d55273468a0a16fe2
Merge "[FEATURE]m.Column: Display popin without header."
Merge "[INTERNAL] Minor fixes to margin samples and qunit tests"