systick: Refactoring.
Merge pull request #152 from dpc/systick

systick: Refactoring into ioreg
Move zinc crate source into a subdir

This also renames the Zinc file from main.rs to lib.rs, and subsequently
the lib mod to util.
Merge pull request #164 from bharrisau/folder

Move zinc crate source into a subdir
k20: Introduce `app_blink_k20_isr`.
Merge pull request #162 from dpc/app_blink_k20_isr

k20: Introduce `app_blink_k20_isr`.
Various fixes thanks to rfc 49

(https://github.com/nikomatsakis/rfcs/blob/master/active/0049-bounds-on-object-and-generic-types.md)
Linter is happy on tests
Fixed param bound for os PT
Merge pull request #165 from farcaller/fix-nightly

Various nightly fallout fixes
Moved all rust code into src
Merge pull request #167 from farcaller/toss-code-around

Moved all rust code into src
Do not allow to relocate code, fixes kcov
Merge pull request #168 from farcaller/fix-coverage

Fix coverage reports
ioreg: Port to syntax::ptr::P
platformtree: Port to syntax::ptr::P
Merge pull request #171 from bgamari/master

Nightly fallout
Range patterns now use ...
ioreg: Nightly churn

Mostly issues due to GC disappearing
Vec::append_one is deprecated; replace with push