installer: Add "mingw" and "DevEnv" to the large wizard image

The logo text is using the "Adelle Bold" font which is freely available at

http://type-together.com/newsletters/2010-01.html

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Generate git-small.bmp from Git-Icon-1788C.eps via a script

The script calls ImageMagick's "convert" which needs to be in your PATH.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Rename the icon rasterization script for consistency

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Simplify the icon rasterization script a bit

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Write icon images largest to smallest for increased compatibility with Tk

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
installer: Only prefix the version number with "v" as part of the file name

This avoids text like "version v0.1" in the installer where the version is
redundant and restores the behavior before e2e3e41.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
installer: Negate the logo color as a further differentiator

This is to distinguish even more from the Git for Windows end user
installer.

Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>