The nghttp2 autobuild package has copyright information that embeds a newline.
autobuild install --copyrights correctly produces that information onto two
lines. But that means packages-formatter.py must process any lines that do not
match its expected 'packagename: copyright' pattern as the continuation of the
preceding package's copyright information.

Since the processing for autobuild install --versions is so very similar, fold
both into the same outer loop.

Also report all duplicates for any package, instead of stopping at the first.

SL-409 - added tracking for bytes fetched to viewer assets metrics (does not currently work for textures)

SL-109 - added another diagnostic option for skel_tool.py. --slider_info dumps the info about bone-affecting sliders to stdout

SL-315 - arche_tool.py updates, resetSkeleton() now preserves mPelvis state, forces all params to be updated.

SL-375, SL-378 - rudimentary logging info to list joint offsets during mesh import. dae_tool.py work to enable joint offset tweaking.

SL-344 - fixed a problem in avatar_lad with some params in wrong group, added diagnostics to make this easier to detect.

SL-338 - added --set_version to anim_tool.py, for creating files to test upload of unsupported file versions.

Ensure that AUTOBUILD is always in native path syntax on every platform.
Remove local build.sh logic to infer AUTOBUILD: either the generic build.sh
has set it properly, or scream for help.
Since cygwin bash scripts need a cygwin-syntax path to autobuild, convert to a
local 'autobuild' variable using shell_path.
Remove kludges in other languages involving cygdrive twiddling.

Hopefully this will make certain errors clearer, notably failure to launch
autobuild due to "cannot find the file specified".