fontforge: make python an optional dependency.
libstfl: make python an optional dependency.
libtorrent-rasterbar: make python optional.
libxml2: make python an optional dependency.
llvm: make python an optional dependency.
postgres-xc: make python an optional dependency.
postgresql: make python an optional dependency.
libtorrent-rasterbar: add 0.16.16 bottle.
llvm: add 3.4 bottle.
fontforge: add 20120731_1 bottle.
postgres-xc: add 1.0.3 bottle.
postgresql: update 9.3.4 bottle.
libxml2: update 2.9.1 bottle.
libstfl: add 0.22 bottle.

Closes #29066.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
sqlite: add ICU extension

This commit adds the option to integrate the "International Components for Unicode" library for SQLite.

See https://www.sqlite.org/src/artifact?ci=trunk&filename=ext/icu/README.txt for more information.
sqlite: update 3.8.4.3 bottle.