Implements issue #158
Improve testing.
Test issue #145
Merge branch 'issue_158' into issue_145

Conflicts:
	src/collective/cover/tests/test_basic_tile.py
Improve image populate
Merge branch 'issue_158' into issue_145
Fix issue #145
Fix issue #137
update changelog and some improvements.
Fix test suite...
Missing file...
Implements an original size scale to show the original image.
changelog...
Trigger Travis
typo
Merge pull request #162 from collective/issue_156

Issue 156
Merge pull request #160 from collective/issue_145

Fixes Issue 145
Merge pull request #161 from collective/issue_137

Fix issue #137
add test to demonstrate bug reported in #166
revert 9ba5119c8cd3d663e554d7715210223bd5c73425, breaks tiles edition.