Add more services and some fixes, along with more "override"
in the service's headers
Added DeleteFile and DeleteDirectory functions to FS:USER and the archives.
Merge pull request #190 from purpasmart96/more_services

Add more services and general fixes
Add comment style notes to CONTRIBUTING.md

Closes #215
Update CONTRIBUTING.md
Merge pull request #220 from yuriks/patch-1

Add comment style notes to CONTRIBUTING.md
Merge pull request #191 from archshift/deletexyz

Added DeleteFile and DeleteDirectory functions to FS:USER and the archives.
Change some SkyEye defines to const ints

This prevents them from interfering with other constants defined in
different namespaces.
HLE: Revamp error handling throrough the HLE code

All service calls in the CTR OS return result codes indicating the
success or failure of the call. Previous to this commit, Citra's HLE
emulation of services and the kernel universally either ignored errors
or returned dummy -1 error codes.

This commit makes an initial effort to provide an infrastructure for
error reporting and propagation which can be use going forward to make
HLE calls accurately return errors as the original system. A few parts
of the code have been updated to use the new system where applicable.

One part of this effort is the definition of the `ResultCode` type,
which provides facilities for constructing and parsing error codes in
the structured format used by the CTR.

The `ResultVal` type builds on `ResultCode` by providing a container for
values returned by function that can report errors. It enforces that
correct error checking will be done on function returns by preventing
the use of the return value if the function returned an error code.

Currently this change is mostly internal since errors are still
suppressed on the ARM<->HLE border, as a temporary compatibility hack.
As functionality is implemented and tested this hack can be eventually
removed.
Remove duplicated docs/update them for changed parameters.
Use pointers instead of passing handles around in some functions.