[ui] adjust status bar button for XP

[ui] use a toolbar button for the checksum

* Also fix tabbing order for controls
* Also provide the name of the image in the checksum report

[ui] add new dialog to display MD5 & SHA-1

[internal] use DialogIndirect to reduce the number of dialogs in the RC

* Since Microsoft forces our hand, we hack away into our compiled RC
  resources and change dialog attributes on the fly so that:
  - we can switch between LTR & RTL
  - change the font for Windows XP
* Note that the base RC font has been changed to "Segoe UI Symbols"
  so that it looks the same in the editor (at least for English) but
  can accommodate the length required for "MS Shell Dlg"

[ui] use a hidden button on the status bar to generate the hash

* Also add a tooltip for the language bar
* Also reduce the size of the icon in README.md

disable MS-DOS creation for Windows 10 or later

* Microsoft removed the diskcopy.dll that contained the MS-DOS floppy image
  Not a big loss, since we have FreeDOS... ;)
* Closes pbatard#545
* Also apply a long overdue refactoring for boot and target types
* Also update the README to add an icon

[ui] add a status bar button to initiate checksum computation

* Just click the "hash" sign to get a hash
* Also clean up status bar related functions

[misc] fix WDK compilation and optimize checksums

[misc] add MD5 and SHA-1 computation for current image

* Uses the Alt-M cheat mode for now
* Closes pbatard#475

[core] make sure the system disk is never listed

* When using VHD or VMDK drives, it was possible for the system disk to be listed.
* Closes pbatard#541