Generate Windows icon for both Eclipse 3.4 and 4.2 launchers

According to component that customizes the icon of a Windows .exe
launcher [1], the Eclipse 3.4 launcher requires an .ico file with the 7
images (in any order):
- 16x16, 8 bit (256 colors)
- 24x24, 8 bit (256 colors)
- 32x32, 8 bit (256 colors)
- 48x48, 8 bit (256 colors)
- 16x16, 32 bit (RGB / Alpha Channel)
- 32x32, 32 bit (RGB / Alpha Channel)
- 48x48, 32 bit (RGB / Alpha Channel)

A user icon matching exactly the width/height/depth of an executable
icon will be written to the executable and will replace that executable
icon. If an executable icon does not match a user icon, it is silently
left as is.

Current neo.ico doesn't comply as it contains compressed images
(through 3 to 7) and has no 24x24, 8 bit (256 colors) icon:

    > identify -format '%f %p/%n %m %C/%Q %r %G %A %z\n' repository/icons/obj16/neo.ico
    neo.ico 0/7 ICO Undefined/0 DirectClass sRGB Matte 48x48 True 8
    neo.ico 1/7 ICO Undefined/0 DirectClass sRGB Matte 32x32 True 8
    neo.ico 2/7 ICO Undefined/0 DirectClass sRGB Matte 16x16 True 8
    neo.ico 3/7 ICO Zip/0 DirectClass sRGB Matte 256x256 True 8
    neo.ico 4/7 ICO Zip/0 DirectClass sRGB Matte 48x48 True 32
    neo.ico 5/7 ICO Zip/0 DirectClass sRGB Matte 32x32 True 32
    neo.ico 6/7 ICO Zip/0 DirectClass sRGB Matte 16x16 True 32

Lets generate a new Windows icon using PNG icon from Neo4J Desktop [2],
with ImageMagick:

    > convert repository/icons/obj16/neo4j-icon_512x512.png -border 0 -compress None \
        \( -clone 0 -resize 16x16 -colors 256 -depth 8 \) \
        \( -clone 0 -resize 24x24 -colors 256 -depth 8 \) \
        \( -clone 0 -resize 32x32 -colors 256 -depth 8 \) \
        \( -clone 0 -resize 48x48 -colors 256 -depth 8 \) \
        \( -clone 0 -resize 16x16 -depth 24 \) \
        \( -clone 0 -resize 32x32 -depth 24 \) \
        \( -clone 0 -resize 48x48 -depth 24 \) \
        \( -clone 0 -resize 256x256 -depth 24 \) \
        -delete 0 -alpha off repository/icons/obj16/neo.ico

New icon has no compressed parts, includes missing 24x24, 8 bit (256
colors) icon and adds 256x256, 32 bit (RGB / Alpha Channel) icon for
the Eclipse 4.2 launcher:

    > identify -format '%f %p/%n %m %C/%Q %r %G %A %z\n' repository/icons/obj16/neo.ico
    neo.ico 0/8 ICO Undefined/0 DirectClass sRGB Matte 16x16 True 8
    neo.ico 1/8 ICO Undefined/0 DirectClass sRGB Matte 24x24 True 8
    neo.ico 2/8 ICO Undefined/0 DirectClass sRGB Matte 32x32 True 8
    neo.ico 3/8 ICO Undefined/0 DirectClass sRGB Matte 48x48 True 8
    neo.ico 4/8 ICO Undefined/0 DirectClass sRGB Matte 16x16 True 32
    neo.ico 5/8 ICO Undefined/0 DirectClass sRGB Matte 32x32 True 32
    neo.ico 6/8 ICO Undefined/0 DirectClass sRGB Matte 48x48 True 32
    neo.ico 7/8 ICO Undefined/0 DirectClass sRGB Matte 256x256 True 32

[1] http://git.eclipse.org/c/equinox/rt.equinox.p2.git/commit/?id=a2f9d54d4ec55e27d28b6c522a2940b309729f11
[2] /neo4j/packaging/neo4j-desktop/src/main/resources/neo4j-icon_512x512.png
Merge pull request #56 from manandbytes/windows-icon

Generate Windows icon for both Eclipse 3.4 and 4.2 launchers