APIv2: geoquery expression in subscriptions

[fgalan]

Issue #1316 is about basic subscription creation, including q filters in the expression field. The present issue is about completing the support of the other elements in expression field: georel, geometry and coords.

This issue should be done after #1677 (given that probably some "reusing" of that is needed in subscriptions).

[fgalan]

The following post at SOF must be edited when this issue gets completed: http://stackoverflow.com/questions/36064565/fiware-orion-subscription-with-georel-expression-in-condition

[fgalan]

Implemented in PR #2397

[fgalan]

Assigned to @iariasleon for final QA verification before closing it.

(If this cannot be checked withitn the 1.3.0 development cycle, it will be moved to QATestPending milestone)

[iariasleon]

This issue has been tested in INT environment, but it should be tested in more detail by the area of component, it is moved to QATestPending milestone.

[iariasleon]

LGTM