Make `popover-arrow-color` default to `popover-bg`

BS3 commits: fcf26d0ef6bc04aa5fb1fc26bee9142b9e1b2818
Fixes 14337: Round .jumbotron corners within .container and .container-fluid

BS3 commits: 0a816e009f5596e4a73afe4380372bf8c16e55cb
grunt
Fixes 14439: Add static tooltip example to docs

BS3 commits: 72ddad6fc88fc7ee9ff99556f1aa64b21539bd03
grunt

BS3 commits: 783e001786e21659a63aae2513a71bb73667c974
grunt. grunt. More screenreader friendly hidden content. grunt

BS3 commits: f5890adb17fe085fdb3a3e5f169102a121dc1e25,
1ebc7e62a8672c59c3bd886bc71ca90e9571d1bc,
a25b866ec7afd7cce613d24c9f5a1955eedc1277,
783e001786e21659a63aae2513a71bb73667c974
grunt. grunt.  Fixes 14348: More screenreader friendly hidden content. Fixes 14337: Round .jumbotron corners within .container and .container-fluid. Fixes 14329: Fixed list-groups nested inside of collapsing panels. Undo the collapse visibility changes since it breaks our collapse plugin. Finish reverting 14444. grunt

BS3 commits: f5890adb17fe085fdb3a3e5f169102a121dc1e25,
1ebc7e62a8672c59c3bd886bc71ca90e9571d1bc,
a25b866ec7afd7cce613d24c9f5a1955eedc1277,
0a816e009f5596e4a73afe4380372bf8c16e55cb,
aa25ce779de9c4c012f7e0b881cddc9719a027cb,
0ec05da0eea03849fc72bed84a2c7fe7be1de1b6,
fe19211e4dee35374803788b24b8c44f1bc179f1,
783e001786e21659a63aae2513a71bb73667c974