Build Fontconfig 2.11 in-tree on Linux

After applying this patch, on Linux you will need to

    ../configure
    make clean-rust-azure clean-fontconfig clean-rust-fontconfig

Fixes #1752.
Renamed HTMLIframeElementTypeId to HTMLIFrameElementTypeId
Install expat-devel on Linux builders
auto merge of #1773 : sawrubh/servo/issue1749, r=Ms2ger
Implement "resize" DOM Event.

* We cannot automate this feature.
* So this testcase is a manual test.
auto merge of #1783 : saneyuki/servo/resize, r=jdm

#1715
auto merge of #1781 : hgentry/servo/mozilla-servo, r=metajack

Simple change. I hope I'm using github correctly; I'm not too familiar with the PR system. Fixes #1777.
De-@mut the script crate.
auto merge of #1755 : jdm/servo/demut, r=jdm,metajack

Requires https://github.com/mozilla-servo/rust-mozjs/pull/49.
Install gperf on Linux builders
Work around missing expat.pc on some RedHat-based systems
Fix link order for azure-test
auto merge of #1780 : kmcallister/servo/linux-fontconfig, r=kmcallister,metajack

After applying this patch, on Linux you will need to

    ../configure
    make clean-rust-azure clean-fontconfig clean-rust-fontconfig

Fixes #1752.

Expect Fontconfig warnings and possibly worse breakage, but for me this makes it possible to use parallel layout at all.
DOMParser should pass the correct contentType (fixes #1741)