[PFW] Integrate PFW core version 3.2.7 release

PFW 3.2.7 release notes:
https://github.com/intel/parameter-framework/releases/tag/v3.2.7



This release contains the following changes:
- Tighter checks on XML attributes
- Travis-related changes
- Documentation fixes
- Fix displaying of syntax errors in EDD files

Bug: 124767636
Test: build

Change-Id: I7b2671156b5275aa2b804246fa65e81613677881
Signed-off-by: Sebastien Guiriec <sebastien.guiriec@renault.com>