hid.cpp: Fixed crash when updating pad data while null

Fixes #137
Add a Doxygen configuration file to generate source docs
Fix compile errors in Clang
Add `override` keyword through the code.

This was automated using `clang-modernize`.
vfp_helper: Get rid of integer type redefinitions
Merge pull request #154 from lioncash/dyncom

vfp_helper: Get rid of integer type redefinitions
Merge pull request #153 from yuriks/add-override

Add override keyword where appropriate
Merge pull request #152 from yuriks/doxyfile

Add a Doxygen configuration file to generate source docs
Merge pull request #141 from archshift/crash-hunt

hid.cpp: Fixed crash when updating pad data while null
Initial WIP of HLE error handling
Second revision
Rename errors.h to result.h
Changed most/all of FS to use ResultCode
Try to fix travis build
Add two remaining missing return codes in FS
Use ResultVal for returns.
ResultVal in a few more places.
Fix bug that I introduced in Archive creation
Attempt to fix Travis build
Change some SkyEye defines to const ints

This prevents them from interfering with other constants defined in
different namespaces.