Enable per hour time-entry

[NicholasSloan]

Timer works only in minutes and seconds, which is fine, but I'd love to be able to enter times in hours, even if "2h" shows up as 120'. (Otherwise an almost perfect app.) The consistent syntax would be 2:1.30 = 2h, 1m, 30 secs. (Not a realistic timing, just to demonstrate the proposal.)