12hour inputchange

Adds 12 hour AM/PM support, enabled by new option "show24Hour" set to false (default true). This and other new options are based on timeEntry by @kbwood (https://github.com/kbwood/timeentry), with which clockpicker works well - see the fiddle http://jsfiddle.net/gitlost/WXD3x/ for an example. The clock hours have been left as is, in 24 hour format - may be confusing.

Also adds tracking input changes with new event handler inputChange(), with setting time from input factored out into a new function, setTime().

Also adds event "clockpickerdone" which is triggered after clockpicker sets the input in done() - generally handy (as mentioned by @vv3d0x in https://github.com/weareoutman/clockpicker/issues/7) and avoids having to listen to "change" in timeEntry case.