Use inline(always) for trace()
Add internal plugin for creating Reflectable implementations
Remove manual impls of Reflectors (autogen)

Obtained via:

 `find . -maxdepth 1 -type f -print0 | xargs -0 sed -z -i "s/\\nimpl Reflectable for[^{]*{[^}]*}[^}]*}\\n//"`
 `find . -maxdepth 1 -type f -print0 |xargs -0  grep -lZ dom_struct | xargs -0 grep -LZ  "reflector()\\|Reflector::new" |xargs -0 sed -z -i "s/use dom::bindings::utils::{Reflectable, Reflector, reflect_dom_object};/use dom::bindings::utils::reflect_dom_object;/"`

followed by semi-automated removal of leftover imports
Remove extra spaces

Command: `find . -maxdepth 1 -type f -print0 | xargs -0 sed -z -i "s/}\\n\\n\\n/}\\n\\n/"`
Add inheritance-checking lint
Ensure that Reflectors are the first field
Fix warnings post-upgrade
plugins: Fix transmute lint message
Remove some transmute calls.
auto merge of #4489 : Manishearth/servo/transmute-lint-fix, r=Ms2ger
auto merge of #4490 : Ms2ger/servo/transmutes, r=jdm
auto merge of #4173 : Manishearth/servo/a-more-dom-struct, r=kmcallister

Now `#[dom_struct]` also generates Reflectable impls, and there's another lint to ensure that a DOM struct only contains one bare DOM field (as the first field) or a Reflector.

A lot of this was generated by sed -- each autogenerated change has its own commit for easy review; these will be squashed later.
Update web-platform-tests.
auto merge of #4494 : Ms2ger/servo/wpt_20141228, r=Manishearth
Added readonly flag for CSSStyleDeclaration
auto merge of #4486 : ProgramFOX/servo/readonly-csssd, r=jdm
Simplify some code in handle_click_event.
Upgrade cssparser to a version with the new ToCss trait.
Implement ToCss for types in style::properties::common_values::specified
Implement ToCss for Cursor and de-duplicate variants and string values.