failsafe version of f9eaa29b
display nothing instead of "null" when description is missing
display nothing instead of "null" when metric is missing
also display event expiration time in the grid
Merge pull request #50 from mfournier/more-grid-ui-nitpicking

More grid ui nitpicking
Merge pull request #48 from mfournier/really-fix-delete-error

failsafe version of f9eaa29b