Added some ways to parse raw files and sections

[Ykidia]

This is mostly related to #426:

• added some ways to parse raw files and sections, introducing "probing" to most parse functions (instead of "inserting" in some of them) for this;
• if ME region does not exist (the region begin specified is higher than end or the region is disabled in some other way), the "Intel image" does not cease to be the "Intel image", this especially noticeable on the Xeon 6 Birch Stream platform, where BootGuard is considered obsolete and disabled ME does not cause problems;
• perhaps, forgotten DVAR item name (re)set;
• parse each volume body in standard common stream instead of parsing volume bodies separately from volume headers.

1st changes allow to detect much more 'hidden" UEFI elements in raw files and sections: NVAR stores, TE/PE32 images, compressed sections...
2nd change allows to detect more Intel images as Intel images :)
Others changes associated but not closely related.