Issue #49: pys file opening switched to new fileio class that allows aborts
Issue #49: Saving pys files now uses new fileio interface
Merge branch 'master' of github.com:manns/pyspread

Conflicts:
	pyspread/src/actions/_grid_actions.py
	pyspread/src/actions/test/test1.pys.sig
	pyspread/src/actions/test/test4.pys.sig
	pyspread/src/lib/fileio.py
	pyspread/src/lib/test/test1.pys.sig