Added option for natural arrow keys

The natural order is used for the arrow keys. Arrow up select the upper
slider value for vertical sliders, arrow right the righter slider value
for a horizontal slider - no matter if the slider was reversed or not.
By default the arrow keys are oriented by arrow up/right to the higher
slider value, arrow down/left to the lower slider value.

Tests are provided.
Updated unit tests names and descriptions
Merge pull request #127 from CostXpertAG/master

Added option for natural arrow keys
refactoring name of natural arrow keys feature; users can now pass optional parameter to 'setValue' function to trigger the 'slide' event
Slide event: don't set an array as the text input value. Test added.
Merge pull request #139 from timmywil/set_value

Slide event: don't set an array as the text input value. Test added.
adding "different platforms" list
changing the link to b-s-knockout
adding reference to angular-bootstrap-slider
adding livereload to gruntfile
Adding custom handle option for slider

Adding custom handle option to allow a 4th kind of slider [custom]
Updating README -> Adding custom value on handle options table
Merge pull request #145 from andredurao/master

Adding custom handle option for slider
Added an option to have a responsive slider

If the slider width or height is set to 100% when you resize the window the slider tooltip doesn't change its position. With this modification you can set a 'data-slider-responsive' attribute that makes the tooltip moving properly on window resizing.
Added an option to have a responsive slider

If the slider width or height is set to 100% when you resize the window the slider tooltip doesn't change its position. With this modification you can set a 'data-slider-responsive' attribute that makes the tooltip moving properly on window resizing.
being more clear on requirements for a PR
Update README.md
noting rebase in contributing doc
Add correct notation for strict maths
Merge pull request #153 from eugenenunan/master

Add correct notation for strict maths