History API: add route/function to enable setting a current/working history; pack scripts
QA, browser tests: fix for history update with non-attribute key (fails silently now); fix for hda create when no from_ld_id is given (now 400)
QA, browser tests: update tooltip selector for Bootstrap 3
Style, history panel: remove unneeded CSS reset
Convert galaxy.frame.css into less-file and import into base.less
Use select2 rather than custom combobox for Trackster dbkey select.
Remove custom combobox (search + select) code because it has been replaced with select2. Pack scripts.
Shift galaxy.upload.css to less format, update modal window according to new bootstrap version
Use to_html_string on failed tests tracebacks and stderr