Grayed out days display on month view

[ridunoff]

Description

Fixed the lastDay variable in actions.js to correctly represent the last day of the month in the month view.
Fixes issue #260

Testing

If the month ends on a Sunday, on the month view, check if events display in the final week's grayed out Monday-Saturday.

If the month ends on a Friday, on the month view, check if the grayed out events display on the grayed-out Saturday.

[coveralls]

Coverage remained the same at 39.245% when pulling 959b91d on iss260 into 299c983 on dev.

[kylecombes]

Thanks for fixing my off-by-one mistake!