There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
All users of get_status_field() expect the field pattern to occur in
the beginning of a line, and the delimiter is ':'.
Hardcode this into the function, and also skip any whitespace before ':'
to support fields in files like /proc/cpuinfo. Add support for returning
the full field value (currently stops on first whitespace).
Rename the function so it's easier to ensure all callers switch to new
semantics.
Introduce a proper enum, and don't pass around string ids anymore. This
simplifies things quite a bit, and makes virtualization detection more
similar to architecture detection.
Virtualbox 5.0 now supports kvm hypervisor. In this case cpuid
identidies as "kvm", which breaks units depending on
ConditionVirtualization=oracle.
So return "oracle" even with kvm hypervisor.
