Upgrade plone.app.blocks
Use relative path to tiles.
Update Changelog
Merge branch 'master' into ericof-plone.app.blocks-1.1

Conflicts:
	docs/HISTORY.rst
Merge branch 'master' into ericof-plone.app.blocks-1.1

Conflicts:
	docs/HISTORY.rst
bump up version of dependency plone.app.blocks to 1.1.1
this solves an issue with VHM and tile rendering
for more information, see: https://dev.plone.org/ticket/13581
Merge branch 'master' into ericof-plone.app.blocks-1.1
Merge pull request #210 from collective/ericof-plone.app.blocks-1.1

fixes #122