Replaced typeof Function checks with jQuery.isFunction() method

Added missing @param markup {} to JavaScript types

Replaced alert() in jQuery version check with new Error
Updated code to resolve several JSHint warnings
Added JSHint support to Travis-CI build process

Added minimally configured jshint.yml
Test whether JSHint is available - trying to avoid using Grunt here
Replaced jshint.xml with .jshintrc
Added new option reverseSortDir to change table header image direction on click events

Packed new release

Updated demo and package options in documentation
Updated reverseSortDir option
Fixed sorting bug introduced in last commit

Packed new release
Fixed another bug due to JSHint change - updated condition

Replaced deprecated jQuery event method .click() with .on()
Packed new release
Fixed broken test case due to missing reverseSortDir option
Updated reverseSortDir option