Adding IDEA specific subdirs to .gitignore
Deprecating getMilliseconds* and getNanoseconds* and add getDuration*
add @since to getDuration, and minor doc tweaks
Fix exception text for bad duration value

It said it expected a string or number of $units,
but really if it's a number it always has to be
milliseconds.
Merge pull request #59 from typesafehub/wip-add-getDuration-√

Wip add get duration √