Fix/mask crash in shader debugger in Mii Maker

Debugger: implement wait tree widget

FS: implement DeleteDirectoryRecursively

GPU: DisplayTransfer & MemoryFill cleanup and param check

They're not currently used, and it's easy to accidentally pass a single
pointer argument to them, causing an out-of-bounds read.

As far as I can tell, memset was replaced by a fill without correcting
the parameter type, causing an out-of-bounds array read in the Vec4
constructor.

OpenGL: Take cached viewport sub-rect into account for scissor

Fixes #1938

the old implementation modifies the loop variable in the loop. Though it actually works, it is really confusing. Makes it morereadable now.

previous commits changes the behaviour of interrupt when meeting invalid params. Regresses to the same behaviour as before
needs more hwtest

prevent further operation with invalid values which may cause assertion failure or divided by zero.
needs more hwtest

RasterizerCachedMemory doesn't has pointer but should be considered as valid

The old code indented too much to read. Split into functions and do general cleanup.

Qt: shutdown system if error on loading ROM

Fix clang-format lint

Add clang-format as part of our {commit,travis}-time checks

Travis: Fix OS X build

Probably due to additional Travis caching, cmake is now already
installed when the script runs. This causes the unlink to remove the
symlink to the executable, which is then not re-added by the install
(since it's already installed).

This makes clang-format useful on those.

Also add a bunch of forgotten transitive includes, which otherwise
prevented compilation.