Put #FFFFFF back into the palette.

Some of the female hairstyles use #FFFFFF, which I had originally changed
to #FAF8F9 when I standardized the palettes -- the two colors weren't
visually distinct. Later it turned out that in some recolors, that extra
color does make a big difference; so, put it back.
Remove #E8CFE4 from the palette.

Page and page2 were non-palette, and used #E8CFE4 incidentally for a few
pixels when they mapped to a palette; use another color instead. Plain
and ponytail2 used #E8CFE4 and #FAF8F9 as the two lightest colors; change
these to use #FAF8F9 and #FFFFFF to match everything else.
Add extract-palette script.
Generate recolors.
Merge branch 'universal-hair' of https://github.com/joewhite/Universal-LPC-spritesheet into universal-hair
Add shadows to the plain and ponytail2 source images. (Not yet used.)
Fixed Hairstyles Up to Date

Fixed all hairstyles I updated before Joe White's changes. Bunches,
Long, Loose, Page, Page2, Princess, and Left/Right Shoulder have the
sixth shade color as well as the fall animations filled out. Also fixed
the hair XCF palette again.
Merge branch 'universal-hair' of https://github.com/joewhite/Universal-LPC-spritesheet into universal-hair