gfx: Refactor the Mac platform goop into platform/
Refactor the Linux font stuff
Remove native.rs. It's no longer needed; just use platform::* directly.
Remove some module aliases.

These aliases were there for old versions of resolve, and are no longer needed.
Refactor glyph.rs to modern Rust coding style
Refactor the HarfBuzz shaper to be in line with modern Rust style
Rename one of the two modules called "shaper"
Hoist all `extern mod` directives to the top level

This improves compile time and makes `use` directives look cleaner.
Nuke the TGA encoder
Add missing platform/mod.rs
removed reference to cairo
Merge pull request #376 from JamieKnight/patch-1

Removed reference to cairo from servo-gfx/font.rs
Fix refactored code on linux.
Merge pull request #1 from metajack/refactor-gfx

Fix refactored code on linux.
Merge remote-tracking branch 'pcwalton/refactor-gfx'

Conflicts:
	src/servo-gfx/font.rs
	src/servo-gfx/font_context.rs
	src/servo-gfx/font_list.rs
	src/servo-gfx/freetype_impl/font_context.rs
	src/servo-gfx/image/encode/tga.rs
	src/servo-gfx/native.rs
	src/servo-gfx/platform/linux/font.rs
	src/servo-gfx/platform/linux/font_list.rs
	src/servo-gfx/platform/macos/font.rs
	src/servo-gfx/quartz/font_context.rs
	src/servo-gfx/quartz/font_list.rs
	src/servo-gfx/servo_gfx.rc
	src/servo-gfx/text/glyph.rs
	src/servo-gfx/text/mod.rs
	src/servo-gfx/text/shaper.rs
	src/servo-gfx/text/shaping/harfbuzz.rs
	src/servo-gfx/text/text_run.rs
Update dependencies.
Merge pull request #377 from metajack/dep-update

Update dependencies.
Fix merge errors from the refactor-gfx merge.
Merge pull request #379 from metajack/fix-merge-errors

Fix merge errors from the refactor-gfx merge.
Update dependencies.