tests for HTML properties, span for col/rowspan
PEP8
PEP 8 and docs
Expose innards to user: not portable between filetypes / importer libraries

Conflicts:
	messytables/excelx.py
Make tests skip if pdftables not installed

Conflicts:
	test/test_any.py
initial stab at cell.properties[item]

Conflicts:
	messytables/html.py
new failing tests
fulfilled tests

Conflicts:
	messytables/html.py
Move CoreProperties to core
??
revert old properties

Conflicts:
	test/test_read.py