JS: update to latest BS3 build
disable user-select for buttons

BS3 commit 08cd3072fc48d8b4ad7e9062cd5e9bbea1cc19da
fixes 8703. fixed 8715

BS3 commits e5a7af36d5a67bb4c3dfa5cc3e9924c3c901d0d3,
edaeb338168e99548e94e59d2d8ed43b95144d7d
docs.css: Remove border-color that's missing a value

BS3 commit 59ad7a9cf454a024ae0c9091d2e37f373181fb27
add responsive images section to docs. add commas in a couple places. expand out IE for consistency w/ the rest of the page. apply <code> in a few places.  CSS docs page: Use simpler HTML5 style for `multiple` boolean attribute of <select>. expand grid system options table to include column widths, gutter widths, large desktop media query, and container widths. avoid ambiguous term "relative sizing"; clarify width vs. height control classes. Deleted "show-grid" class from examples

BS3 commits b0225c073a714c8172d6d59f9b21fc669f1cf747,
e9b1422e8614a8f1deac08941e84d93b1c1f7d5b,
d0a2a62cd774fca9fd2664e0eaf9b93377aa0dbf,
7bcee1acd2e0c96ffb8895f6b72505bc377c8ec1,
774f173a18d93ba5e80d8c4c8207c8f961004da6,
061535019c9b94745c95f4f8215a55bc59b11bdd,
0bf5443ad79c6e708206d5c05baff1d3e253be9e
Javascript - tooltips directions - easier visualization. apply tooltip demo ordering change from 8730 to popovers too. Deleted unnecessary ID from modals example

BS3 commits af90282858daedfd226c71e7b678f93fa37cdd98,
b1a1210f071b696450f323f35b55b399a17d5396,
2acb0f40c058f6893e5bcf63b9cbdc3c9faeed4c
fix html5shiv & respond.js script links in docs

BS3 commit 3a50ce359602b90decf7d038692c28641bcee875