It used to be the case that when updating app.manifest, the resource file
it not automatically rebuilt. This made it a headache to update the manifest.
We set OBJECT_DEPENDS so that cmake knows to make the res file depend on
app.manifest and icon.ico.
This commit is based on PR #579 and should be rebased on it after it's merged.
GCC 11 will support x86_64 micro-architecture feature levels.
What we really want to support is nehalem or newer, which is x86-64-v2,
and specifying this instead of nehalem means that we are not tuning for
nehalem specifically.
Nehalem is the minimum requirement for the host application as it makes
use of SSE4.1 instructions, as such we should default to compling with
it instead of `-march=native` so that when the binary is distributed it
will operate on foreign systems.
Fixed#416
