add link to StackOverflow question regarding Android <select> bug
Remove unneeded spaces from `pre`.
bump grunt-saucelabs to v5.1.3
Merge pull request #13594 from twbs/bump-saucelabs

bump grunt-saucelabs to v5.1.3
more precise docs link
reference other more recent source regarding the IE viewport bug
docs: sort tooltip & container options for sanity
add 'viewport' option to popover docs; #12328 erratum
add multiple triggers info to popover docs
add 'selector' option motivation to tooltip docs
add 'container' option motivation to tooltip docs
update default 'template' value in popover docs
Merge pull request #13601 from twbs/tooltip-popover-doc

Sync tooltip & popover docs
Tweak JS style and the relevant JSHint and JSCS checks.
Comply to the new style.
Remove `laxbreak`.
Remove `boss`.
Enable `es3`.
Switch to using plain `if/else` statements when there's no assignment.

The minifier outputs the same code anyway, and this has better readability.
Minor style tweaks.