Remove dead code
Use fmt::Show for outputting debug information
Use Vec in workqueue.rs.
Use Vec in transform_text tests.
Use Vec for the metadata argument to initialize_layers_for_pipeline.
Return Vec from get_last_resort_font_families.
Use Vec for ResourceTask.
Use Vec in concurrentmap.rs.
auto merge of #2347 : Ms2ger/servo/vec, r=jdm
Print the location of the image diff when a ref test fails.
auto merge of #2349 : zwarich/servo/reftest-print-diff, r=larsbergstrom

Having to match the numbered results in /tmp with the failing tests was bothering me, and I figured it would be better to print the path with the failure.
Remove an unused import of std::str.
Modify node traversal loop to avoid JS roots assertion. Fixes #2321.
Fix JS roots assertion when clicking on an element
auto merge of #2304 : Manishearth/servo/deadcode, r=metajack

The code was added as a debugging method [here](https://github.com/mozilla/servo/commit/5663ca1eef9b2aefbfe9f924c3e0505f1b0266fc), it's no longer used
Rename from_unrooted to from_temporary. Fixes #2332.
auto merge of #2350 : zwarich/servo/unused-str-import, r=metajack
auto merge of #2354 : glennw/servo/issue-2332, r=metajack
auto merge of #2336 : bjz/servo/debug_str, r=pcwalton
auto merge of #2340 : glennw/servo/js-click-assert, r=jdm