Download http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt and place
it as Licenses/LGPLv2.1.txt in our source tree. When building cmake-gui,
use option CMake_GUI_DISTRIBUTE_WITH_Qt_LGPL to enable notification
in the "About" dialog of how the distribution of Qt is licensed.
Install the license file as ${CMAKE_ROOT}/Licenses/LGPLv2.1.txt so that
the dialog can display a path to it.
Set GIT_COMMAND to "git" -- each machine involved in building
the CMake release binaries has the right "git" in the PATH.
Separate the release scripts into two batches so we can build
multiple releases on the same machine, in serial, if necessary.
We currnetly do this with the Windows and Cygwin release
binaries on dash2win64.
Sort the files to be uploaded, so that sorting them by modification
time (file copy / upload time) is equivalent to sorting them
alphabetically.