flip left and right on tooltips and popovers [#67]

[mapmeld]

hi,
here is my idea for how to flip left and right on tooltips and popovers in Bootstrap 3.x (fixing #67). It requires adding code to Bootstrap's JavaScript library too, so I'm not sure how you would want to organize /dist/js or the examples/originals/dist folder.

Main changes:

• added a js/bootstrap-rtl-addons.js which patches in a right-left change to Tooltip and Popover plugins
• added grunt-contrib-uglify package and task, so the build will create a bootstrap-rtl.min.js file
• for arrow.left to become RTL, use styles from the LTR arrow.right and overwrite LTR's arrow.left styles. Repeated for arrow.right
• include tooltip.less in the files checked by bootstrap.less