dloader: First step in improving looks of boot menu

The boot menu essentially hasn't changed since it was converted to C
a few years ago.  The line between Fred and menu always bugged me, but I
suppose some people like it.  I added a new loader option called
"fred_separated" that is off by default, but if set on in loader.conf,
it will bring back the line.  When the line isn't present, Fred shifts
over by two characters which makes him centered.

While here, improve the colorization of Fred.  Colorization is not turned
on by default.  Before that can happen, adequate detection for a serial
console must be added to avoid using ansi color codes on it.

Since Fred has always been depicted as a red DragonFly with red wings, he
has been given bright red wings against a darker red body, and eyes have
changed from green yellow.  His shape has been tweaked as well.  His
scorpion stinger was sanded down to a small point and his mosquito beak
was made shorter so his head looks more like a DragonFly.  His thorax was
improved with curly brackets.

The original look can be restored by putting this in /boot/loader.conf:
  fred_separated="YES"

Approved by: Positive feedback on IRC channel
drm/i915: i915_gem_do_init() is i915_gem_init_global_gtt()

Drop it and reduce differences with Linux 3.8.13 in the code using it.
dloader: Add a new option for color loader, "fred_is_blue"

When loader_color="YES", the dragonfly logo will show Fred as a red
dragonfly with red wings.  If fred_is_blue="YES" is set in loader.conf
as well, then a blue version of Fred will show instead (slightly more
fancy as wings are two-tone).

While here, update the man page with this new option and document
"fred_separated" option which was added yesterday.
kernel: Remove the no longer used KTR_USB_MEMORY option.
kernel/acpi: Add two debug tunables, debug.acpi.{ignore_xsdt,fadt_addr32}.

Used for affecting AcpiGbl_DoNotUseXsdt and AcpiGbl_Use32BitFadtAddresses,
which came in with 20131218.